#include <iostream>
#include <vector>
using namespace std;
int main(){
    int n, m, t, a, b;
    cin >> n >> m;
    vector <int> f(n + 1, 0);
    for(int i = 1; i <= n; ++i){
        cin >> t;
        f[i] = f[i - 1] + t;
    }
    while(m--){
        cin >> a >> b;
        cout << f[b] - f[a - 1] << endl;
    }
    return 0;
}