#include <iostream>
using namespace std;
const int N = 100010;
int n,m;
int a[N],s[N];
int main()
{
    scanf("%d%d", &n, &m);
    for (int i = 1; i <=n; i ++ ) cin >>  a[i];
    for (int i = 1; i <=n; i ++ ) s[i]=s[i-1]+a[i];
    while (m -- ){
        int l,r;
        cin >> l >>r;
        printf("%d\n",s[r]-s[l-1]);
    }
    return 0;
}