#include <iostream>

using namespace std; 

const int N = 100000 + 10;

int n, m;
int a[N], 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;
}