#include<bits/stdc++.h>
using namespace std;
int n,m,k,a[1001],b[1001],sx,sy;
int main(){
    cin>>n>>k;
    for(int i=1;i<=n;i++){
        cin>>a[i];
        b[i]=b[i-1]+a[i];
    } 
    while(k--){
        scanf("%d%d",&sx,&sy);
        printf("%d\n",b[sy]-b[sx-1]);
    }
}
/**************************************************************
	Problem: 2060
	User: wuyunfeng
	Language: C
	Result: Compile Error
****************************************************************/