#include<bits/stdc++.h>
using namespace std;
int main(){
	int n,m,a[10000],b[10000],x,y;
	cin>>n>>m;
	for(int i=1;i<=n;i++){
		cin>>a[i];
		b[i]=a[i]+b[i-1];
	}
	for(int i=1;i<=m;i++){
		cin>>x>>y;
		cout<<b[y]-b[x-1]<<endl;
	}
	return 0;
}

/**************************************************************
	Problem: 2060
	User: chenjingqi
	Language: C++
	Result: Runtime Error
****************************************************************/