#include <bits/stdc++.h>
using namespace std;
#define accelerate ios::sync_with_stdio(false),cin.tie(0),cout.tie(0)
#define endl "\n";
#define mod 12345
#define ll long long
#define PII pair<int,int>
#define INF 0x3f3f3f3f
const int N=1e5+10;
ll n,m,k,x,y,T;
ll a[N];
ll pre[N];
int main(){
	accelerate;
	cin>>n>>m;
	for(int i=1;i<=n;i++){
		cin>>a[i];
		pre[i]=a[i]+pre[i-1];
	}
	while(m--){
		cin>>x>>y;
		cout<<pre[y]-pre[x-1]<<endl;
	}
	return 0;
}