//第二遍微错
#include <iostream>
using namespace std;
const int N = 1e5 + 10;
int a[N], s[N];
int main(){
int n, k;
scanf("%d%d", &n, &k);
for(int i = 1; i <= n; i ++)
scanf("%d", &a[i]);
s[0] = 0;
for(int i = 1; i <= n; i ++)
s[i] = s[i - 1] + a[i]; //注意是s[i - 1] + a[i],用s[i]就错啦
while(k --){
int l, r;
scanf("%d%d", &l, &r);
printf("%d\n", s[r] - s[l - 1]);
}
return 0;
}