#include<bits/stdc++.h>
using namespace std;
int n,m,a[100001],b[100001],x,y;
int main(){
    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]);
    }
}
 
/**************************************************************
	Problem: 2060
	User: huangyikai
	Language: C++
	Result: Accepted
	Time:272 ms
	Memory:2860 kb
****************************************************************/