#include <cstdio>
#include <algorithm>
const int N = 1e5 + 10;
int n, m;
int a[N];
int main()
{
scanf("%d%d", &n, &m);
for (int i = 1; i <= n; i ++ )
{
scanf("%d", &a[i]);
a[i] += a[i - 1]; //一边读入一边构造前缀和数组
}
while (m -- )
{
int l, r;
scanf("%d%d", &l, &r);
printf("%d\n", a[r] - a[l - 1]); //前缀和公式
}
return 0;
}