#include <bits/stdc++.h>//直接使用万能头
using namespace std;
const int N = 1e6 + 10;
int a[N],n,m,qzh[N]; 
#define int long long
signed main(){
	cin >> n >> m;
	cin >> a[0];
	qzh[0] = a[0];
	for(int i = 1;i < n;i++){
		cin >> a[i];
		qzh[i] = qzh[i - 1] + a[i];
	}
	for(int i = 1;i <= m;i++){
		int l,r;
		cin >> l >> r;
		if(l == 1) cout << qzh[r - 1];
		else{
			cout << qzh[r - 1] - qzh[l - 2];
		}
		cout << endl;
	}
}