#include<bits/stdc++.h>
using namespace std;

const int N = 100010;
int a[N], s[N];

int main() {
    int n, m;
    scanf("%d%d", &n, &m);

    for (int i = 1; i <= n; i++) {
        scanf("%d", &a[i]);
        s[i] = s[i - 1] + a[i];
    }

    while (m--) {
        int l, r;
        scanf("%d%d", &l, &r);
        printf("%d\n", s[r] - s[l - 1]);
    }

    return 0;
}