#include<bits/stdc++.h>
using namespace std;
int n,m,x,y,a[100001],b[100001];
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]);
	}
    return 0;
}


/**************************************************************
	Problem: 2060
	User: zhuangsongyu
	Language: C++
	Result: Accepted
	Time:842 ms
	Memory:2860 kb
****************************************************************/