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