#include<bits/stdc++.h>
#define FOR(x,y) for(int i=x;i<=y;i++)
using namespace std;
const int mod = 998244353; 
const int N = 1e6;
int n,m,l,r,a[N],b[N];
int main (){
	cin >> n >> m;
	FOR(1,n){
		cin>>a[i];
		b[i]=b[i-1]+a[i];
	}
	FOR(1,m){
		cin>>l>>r;
		cout<<b[r]-b[l-1]<<endl;
	}
}