#include<bits/stdc++.h>
using namespace std;
int n,m,k,a[100001],b[100001],sx,sy;
int main(){
    scanf("%d%d",&n,&k);
    for(int i=1;i<=n;i++){
        scanf("%d",&a[i]);
        b[i]=b[i-1]+a[i];
    }
    while(k--){
        scanf("%d%d",&sx,&sy);
        printf("%d\n",b[sy]-b[sx-1]);
    }
}
/**************************************************************
	Problem: 2060
	User: linlinzi
	Language: C++
	Result: Accepted
	Time:307 ms
	Memory:2860 kb
****************************************************************/