#include<bits/stdc++.h>
using namespace std;
int n,m,x,y,a[100001],b[100001]; 
int main(){
    cin>>n>>m;
    for(int i=1;i<=n;i++) {
        cin>>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: wangyichen2
	Language: C++
	Result: Accepted
	Time:296 ms
	Memory:2860 kb
****************************************************************/