#include <bits/stdc++.h>
using namespace std;
int a[100001];
int b[100001];
bool f[100001];
int main(){
    int n,m,i,j,x,p=0;
    cin>>m>>n;
    for(j=1; j<=m; ++j){
        cin>>x;
        a[x]=p;
        p=x;
    }
   // for(j=1; j<=m; ++j) cout<<a[j]<<" . "; cout<<endl;
    for(i=2; i<=n; ++i){
        p=0;
        for(j=1; j<=m; ++j){
            cin>>x;
            b[x]=p;
            p=x;
        }
        //for(j=1; j<=m; ++j) cout<<b[j]<<" . "; cout<<endl;
        for(j=1; j<=m; ++j)
            if(a[j]!=b[j])
                f[j]=1;
    }
    int s1=0,s=0;
    for(j=2; j<=m; ++j){
        if(!f[j])
            ++s1;
        else
            s+=s1*(s1+1)/2, s1=0;
    }
    s+=s1*(s1+1)/2;
    cout<<s+m;
    return 0;
}