/****************************
   presented by xingcode
****************************/
#include<bits/stdc++.h>
using namespace std;
int n,m,f[1000005],x,y;
int main()
{    
    cin>>n>>m;
    for(int i=1;i<=n;i++) {
    	cin>>x;
    	f[i]=f[i-1]+x;
	}
	while(m--) {
		cin>>x>>y;
		cout<<f[y]-f[x-1]<<"\n";
	}
    return 0;
}
/*****************************
        do not copy!!!
*****************************/