#1 AC 但是#2-#6 WA #7-#10 RE 求调

#include <bits/stdc++.h>
using namespace std;
int a[1000001], b[100001], ld[100001];

long long xds(int l, int r, int now) {
	if (l == r) {
		a[now] = b[l];
		return a[now];
	}
	long long mid = (l + r) / 2;
	a[now] = xds(l, mid, now * 2) + xds(mid + 1, r, now * 2 + 1);
	return a[now];
}
void push_down(int l,int r,int now){
	if(l==r){
		return;
	}
	if(ld[now]){
		a[now*2]=a[now*2]+((r+l)/2-l+1)*ld[now];
		a[now*2+1]=a[now*2+1]+(r-(r+l)/2)*ld[now];
		if(r-l>2)ld[now*2]=ld[now];
		if(r-l>3)ld[now*2+1]=ld[now];
		ld[now]=0;
	}
}
long long getsum(int l, int r, int sl, int sr, int now) {
	if (l == sl && r == sr){
		return a[now];
	}
	push_down(l,r,now);
	long long sum = 0;
	int mid = (l + r) / 2;
	if (sl <= mid)
		sum += getsum(l, mid, sl, min(sr, mid), now * 2);
	if (sr > mid)
		sum += getsum(mid + 1, r, max(sl, mid + 1), sr, now * 2 + 1);
	return sum;
}

void in2_up(int l, int r, int now, int num) {
	a[now] += num;
	if (now == 1)
		return;
	if (now % 2)
		in2_up(2 * l - r - 2, r, (now - 1) / 2, num);
	else
		in2_up(l, 2 * r - l, now / 2, num);
	return;
}

//mid=(l+r)/2=>l+r=2mid=>l=2mid-r=>l=2(mid+1)-r-2
void inner_up(int l, int r, int now, long long num) {
	a[now]+=num;
	if (l == r) {
		return;
	}
	int mid = (l + r) / 2;
	inner_up(l, mid, now * 2, num), inner_up(mid + 1, r, now * 2 + 1, num);
	return;
}

void update(int l, int r, int sl, int sr, int now, int num) {
	if (l == sl && r == sr) {
		in2_up(l, r, now, (r-l+1)*num);
		if(l!=r)ld[now]=num;
		return;
	}
	int mid = (l + r) / 2;
	if (sl <= mid)
		update(l, mid, sl, min(sr, mid), now * 2, num);
	if (sr > mid)
		update(mid + 1, r, max(sl, mid + 1), sr, now * 2 + 1, num);
	return;
}

int main() {
	int n = 0, m = 0, temp = 0, t1 = 0, t2 = 0, t3 = 0;
	cin >> n >> m;
	for (int i = 1; i <= n; i++) {
		cin >> b[i];
	}
	xds(1, n, 1);
	for (int i = 1; i <= m; i++) {
		cin >> temp;
		if (temp == 1) {
			cin >> t1 >> t2 >> t3;
			update(1, n, t1, t2, 1, t3);
		} else {
			cin >> t1 >> t2;
			cout << getsum(1, n, t1, t2, 1) << endl;
//			for(int ii=1;ii<=2*n+1;ii++)cout<<a[ii]<<" ";
//			cout<<endl;
//			for(int ii=1;ii<=2*n+1;ii++)cout<<ld[ii]<<" ";
//			cout<<endl;
		}
	}
}