#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]);
        s[i] = s[i-1] + a[i];
    }

    while(m--)
    {
        int l,r;
        cin >> l >> r;
        cout << s[r] - s[l-1] << endl;
    }



    return 0;
}