#include <iostream>

using namespace std;

const int N = 1e5 + 10;
int n, m;
int a[N];
int s[N];

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