#include <bits/stdc++.h>
#define int long long
#define ll long long
#define FILE_READ_IN freopen("input.txt","r",stdin);
#define FILE_READ_OUT freopen("output.txt","w",stdout);
#define Fast ios_base::sync_with_stdio(false);cin.tie();cout.tie();
#define endl '\n'
using namespace std;


void judge() {
#ifndef ONLINE_JUDGE
	FILE_READ_IN
	FILE_READ_OUT
#endif
}
const int N = 2e5 + 1;
int n, q;
// the input array
int a[N];
// the segment tree
int t[4 * N];
// for storing lazy set updates
int change[4 * N];
// for storing lazy increase
int inc[4 * N];

void build(int n, int s, int e) {
	if (s == e) {
		t[n] = a[s];
		return;
	}
	int m = (s + e) / 2;
	build(2 * n, s, m);
	build(2 * n + 1, m + 1, e);
	// normal merging sum
	t[n] = t[2 * n] + t[2 * n + 1];
}

void lazy(int n, int s, int e) {
	// if the lazy increase is having some value then it has not been updated
	if (inc[n]) {
		// changing the value in current node
		t[n] += ((e - s + 1ll) * inc[n]);
		// change child is having some value then the set updates haven't reached the child and so the lazy set update has to increased
		if (change[2 * n])change[2 * n] += inc[n];
		else
			inc[2 * n] += inc[n]; // otherwise we increase the lazy increase update
		if (change[2 * n + 1])change[2 * n + 1] += inc[n];
		else
			inc[2 * n + 1] += inc[n];
		inc[n] = 0;
	}
	if (change[n]) {
		// if change is having value then this will overwrite any other updates
		t[n] = (e - s + 1ll) * change[n];
		// passes the updates to the children
		change[2 * n] = change[n];
		change[2 * n + 1] = change[n];
		change[n] = 0;
		// inc[n] = 0;
	}
}

int query(int n, int s, int e, int l, int r) {
	lazy(n, s, e);
	// out of range case
	if (s > e || s > r || e < l)return 0;
	// in range case
	if (s >= l && e <= r) {
		return t[n];
	}
	int m = (s + e) / 2;
	int x = query(2 * n, s, m, l, r);
	int y = query(2 * n + 1, m + 1, e, l, r);
	t[n] = t[2 * n] + t[2 * n + 1];
	return x + y;
}

void updatecha(int n, int s, int e, int l, int r, int val) {
	lazy(n, s, e);
	// out of range case
	if (s > e || s > r || e < l)return;
	// in range case
	if (s >= l && e <= r) {
		t[n] = (e - s + 1ll) * val;
		change[2 * n] = val;
		change[2 * n + 1] = val;
		return;
	}
	int m = (s + e) / 2;
	updatecha(2 * n, s, m, l, r, val);
	updatecha(2 * n + 1, m + 1, e, l, r, val);
	t[n] = t[2 * n] + t[2 * n + 1];
}

void updateinc(int n, int s, int e, int l, int r, int val) {
	lazy(n, s, e);
	// out of range case
	if (s > e || s > r || e < l)return;
	// in range case
	if (s >= l && e <= r) {
		t[n] += ((e - s + 1ll) * val);
		if (change[2 * n])change[2 * n] += val;
		else
			inc[2 * n] += val;
		if (change[2 * n + 1])change[2 * n + 1] += val;
		else
			inc[2 * n + 1] += val;
		return;
	}
	int m = (s + e) / 2;
	updateinc(2 * n, s, m, l, r, val);
	updateinc(2 * n + 1, m + 1, e, l, r, val);
	t[n] = t[2 * n] + t[2 * n + 1];
}

signed main() {
	Fast;
	int t = 1;
	judge();
	// cin >> t;
	while (t--) {
		cin >> n >> q;
		for (int i = 1; i <= n; i++)cin >> a[i];
		build(1, 1, n);
		for (int i = 0; i < q; i++) {
			int op, l, r;
			cin >> op >> l >> r;
			if (op <= 2) {
				int x;
				cin >> x;
				if (op == 2) {
					updatecha(1, 1, n, l, r, x);
				}
				else {
					updateinc(1, 1, n, l, r, x);
				}
			}
			else {
				cout << query(1, 1, n, l, r) << endl;
			}
		}
	}
}