...

#include<iostream>
using namespace std;
int a[1000005];
int main(){
int n , m;
cin >> n >> m;
for(int i = 1;i <= n;i++){
int x;
cin >> x;
a[i] = x + a[i-1];
}
for(int i = 1;i <= m;i++){
int x , y;
cin >> x >> y;
cout << a[y] - a[x-1] << endl;
}
return 0;
}