#include <iostream>
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]);
for (int i = 1; i <= n; i ++) s[i] = s[i - 1] + a[i];
while (m --) {
int l, r;
scanf("%d%d", &l, &r);
cout << s[r] - s[l - 1] << endl;
}
return 0;
}