#include <iostream>
using namespace std;

int main() {
    int n,m;
    cin >> n >> m;
    int arr[n];
    for (int i = 0;i < n;i++) {
        cin >> arr[i];
    }
    int sum[n] = {0,};
    //sum[0]=arr[0];
    for (int i = 0;i < n;i++) {
         for (int j = 0;j < i;j++) {
             sum[i]+= arr[j];
         }
        //cout << sum[i] << "\n";
    }
    for (int i = 0;i < m;i++) {
        int a,b;
        cin >> a >> b;
        cout << sum[b]-sum[a-1] << "\n";
    }
    return 0;
}