#include<bits/stdc++.h>
int n,m,a[100001],b[100001],x,y;
using namespace std;
int main(){
    scanf("%d%d",&n,&m);
    for(int i=1;i<=n;i++){
        scanf("%d",&a[i]);
        b[i]=a[i]+b[i-1];
    }
    while(m--){
        scanf("%d%d",&x,&y);
        printf("%d\n",b[y]-b[x-1]);
    }
}
/**************************************************************
	Problem: 2060
	User: wuyunfeng
	Language: C++
	Result: Accepted
	Time:233 ms
	Memory:2860 kb
****************************************************************/