#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
/// <<------------------------------------------------------------------------------>>
void init()
{
    cin.tie(0);
    cin.sync_with_stdio(0);
    cout.tie(0);
    // Reading From File
    freopen("Shower.in","r",stdin);
}
/// <<----;------------------------------------------------------------------------->>
int main()
{
    init();
    ll n, T;
    cin >> n >> T;
    ll t[n];
    for(int i = 0;i < n; i++)
     cin >>t[i];
    ll cnt = T;
    ll pos = T;
    for(int i = 1 ;i <n ;i++)
    {
        if(t[i] < pos)
        {
            cnt -= (pos - t[i]);
        }
        cnt += T;
        pos  = t[i] + T;
    }
    cout << cnt;
}

import java.io.File;
import java.util.Scanner;
public class AIC {
	public static void main(String[]args) throws Exception {
	// Reading from file
	File f =new File("Shower.in");
	Scanner input=new Scanner(f);
	int n, T;
	n = input.nextInt();
	T = input.nextInt();
	int t[] = new int [n];
	for(int i = 0;i < n ;i++)
	{
	  t[i] = input.nextInt();
	}
	long cnt = T;
	long pos = T;
    for(int i = 1 ;i <n ;i++)
    {
        if(t[i] < pos)
        {
            cnt -= (pos - t[i]);
        }
        cnt += T;
        pos  = t[i] + T;
    }
	System.out.print(cnt);
  }
}

#include <bits/stdc++.h>
using namespace std;
#define endl '\n'
/// <<------------------------------------------------------------------------------>>
void init()
{
    cin.tie(0);
    cin.sync_with_stdio(0);
    cout.tie(0);
    //Reading From File
    freopen("Cinema.in","r",stdin);
}
/// <<----;------------------------------------------------------------------------->>
int main()
{
    init();
    int x,y,z;
    cin >> x >> y >> z;
    int l   = y + z;
    int n   = (x - z) / l; 
    cout << n;
}

import java.io.File;
import java.util.Scanner;
public class AIC {
	public static void main(String[]args) throws Exception {
	// Reading from file
	File f =new File("Cinema.in ");
	Scanner input=new Scanner(f);
	int x, y, z;
	x = input.nextInt();
	y = input.nextInt();
	z = input.nextInt();
	int l = y + z;
	int n = (x - z) / l;
	System.out.print(n);
  }
}

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
void init()
{
    cin.tie(0);
    cin.sync_with_stdio(0);
    cout.tie(0);
    freopen("square.in","r",stdin);
}
/// <<----;------------------------------------------------------------------------->>
int main()
{
    init();
    int n;
    cin >> n;
    for(int i = 31622 ;i >= 1; i--) // i = sqrt(1e9)
    {
        if(i * i <= n)
        {
            cout << i*i;
            return 0;
        }
    }
}

import java.io.File;
import java.util.Scanner;
public class AIC {
	public static void main(String[]args) throws Exception {
	// Reading from file
	File f =new File("square.in");
	Scanner input=new Scanner(f);
	int n = input.nextInt();
    for(int i = 31622 ;i >= 1; i--) // i = sqrt(1e9)
    {
        if(i * i <= n)
        {
            System.out.print(i*i);
            break;
        }
    }
  }
}

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
void init()
{
    cin.tie(0);
    cin.sync_with_stdio(0);
    cout.tie(0);
    freopen("Boxes.in","r",stdin);
}
/// <<----;------------------------------------------------------------------------->>
int main()
{
    init();
    string x;
    cin >> x;
    stack<int>st;
    int n = x.size();
    for(int i=0;i < n; i++)
    {
        if(st.empty())
            st.push(x[i]);
        else if(st.top() == x[i])
            st.push(x[i]);
        else st.pop();
    }
    cout << n - st.size();
}

import java.io.File;
import java.util.*;
import java.io.*; 
import java.util.Stack;
public class AIC {
	public static void main(String[]args) throws Exception {
	// Reading from file
	File f =new File("Boxes.in");
	Scanner input=new Scanner(f);
	String x = input.nextLine();
	int n = x.length();
	Stack st = new Stack();  
	for(int i=0;i < n; i++)
	   {
	        if(st.empty())
	            st.add(x.charAt(i));
	        else if((char)st.peek() == x.charAt(i))
	            st.push(x.charAt(i));
	        else st.pop();
	   }
	System.out.println(n - st.size());
	}
}

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

/// <<------------------------------------------------------------------------------>>
void init()
{
    cin.tie(0);
    cin.sync_with_stdio(0);
    cout.tie(0);
    freopen("tiles.in","r",stdin);
}
/// <<----;------------------------------------------------------------------------->>
int main()
{
    init();
    string x;
    cin >> x;
    int n = x.size();
    string x1 = x;
    int cnt1 = 0 , cnt2 = 0;
    
    for(int i = 1 ;i < n ;i++)
    {
        if(x1[i] == x1[i - 1])
        {
            cnt1++;
            if(x1[i] == '0') x1[i] = '1';
            else x1[i] = '0';
        }
    }
    cnt2 = 1;
    if(x[0] == '1') x[0] = '0';
    else x[0] = '1';
    for(int i = 1 ;i < n ;i++)
    {
        if(x[i] == x[i - 1])
        {
            cnt2++;
            if(x[i] == '0') x[i] = '1';
            else x[i] = '0';
        }
    }
    cout << min(cnt1,cnt2);
}

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

/// <<------------------------------------------------------------------------------>>
void init()
{
    cin.tie(0);
    cin.sync_with_stdio(0);
    cout.tie(0);
    freopen("misbaha.in","r",stdin);
}
/// <<----;------------------------------------------------------------------------->>
int main()
{
    init();
    int n;
    cin >> n;
    int Freq[int(1e5+6)] = {0};
    for(int i = 1 ;i < n;i++)
    {
        int u,v;
        cin >> u >> v;
        Freq[u]++;
        Freq[v]++;
    }
    int cnt = 0;
    for(int i = 1;i <= n;i++)
    {
        if(Freq[i] == 1)
            cnt++;
    }
    cout << cnt;
}

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

/// <<------------------------------------------------------------------------------>>
void init()
{
    cin.tie(0);
    cin.sync_with_stdio(0);
    cout.tie(0);
    freopen("teams.in","r",stdin);
}
int mx;
string rst;
/// <<----;------------------------------------------------------------------------->>
int main()
{
    init();
    int n;
    cin >> n;
    set<string>st;
    map<string,int>mp;
    for(int i = 0;i < 3*n; i++)
    {
        string ipt;
        cin >> ipt;
        st.insert(ipt);
        mp[ipt]++;
    }
    for(string x :st)
    {
        if(mp[x] > mx)
        {
            mx = mp[x];
            rst= x;
        }
    }
    cout << rst;
}

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define  precision(n)  cout << fixed << setprecision(n)
/// <<------------------------------------------------------------------------------>>
void init()
{
    cin.tie(0);
    cin.sync_with_stdio(0);
    cout.tie(0);
    freopen("cell.in","r",stdin);
}
/// <<----;------------------------------------------------------------------------->>
int main()
{
    init();
    int t;
    cin >> t;
    while(t--)
    {
        int A,B, cnt = 1, T = 0;
        cin >> A >> B;
        while(cnt != A)
        {
            cnt *= B;
            T++;
        }
        precision(14) << T << endl;
    }
}

#include <bits/stdc++.h>
using namespace std;
#define endl '\n'
/// <<------------------------------------------------------------------------------>>
void init()
{
    cin.tie(0);
    cin.sync_with_stdio(0);
    cout.tie(0);
    //Reading From File
    freopen("geometry.in","r",stdin);
}
 
 
/// <<----;------------------------------------------------------------------------->>
int main()
{
    init();
    long double L ;
 
	cin >> L ;
 
	long double pi=acos(-1) ;
 
	long double redius = L/2;
 
	long double Area_Of_one_semi_circle = 0.5 * pi * redius * redius ;
 
	long double Area_of_Parabola = Area_Of_one_semi_circle - (redius * redius);
 
	long double Required_Area = .5*L*L - Area_of_Parabola ;
 
	long double perimeter_of_semi_circle = pi * redius ;
 
	long double Required_perimeter = L + L +  perimeter_of_semi_circle ;
 
	cout << fixed << setprecision(6) << Required_Area << " " << Required_perimeter ;
 
	return 0;
}
	

Three pointers ...