#include<bits/stdc++.h>
using namespace std;
int a[100010],b[100010];
int main(){
int n,m,x,y;
    cin>>n>>m;
    for(int i=1;i<=n;i++){
    	cin>>a[i];
    	b[i]=b[i-1]+a[i];
    }
    while(m--){
    	scanf("%d%d",&x,&y);
    	printf("%d\n",b[y]-b[x-1]);
    }
	return 0;
}
/**************************************************************
	Problem: 2060
	User: fuhongyi
	Language: C++
	Result: Accepted
	Time:263 ms
	Memory:2860 kb
****************************************************************/