Shared code

/* 777 */
#include "bits/stdc++.h"
using namespace std;

#define int long long 

// const int MOD=1e9+7;
vector<int>vec;

void solve(){
	int n,q;cin>>n>>q;
	vec.resize(n);
	for(auto &x:vec)cin>>x;
	vector<int>prefix_sum={0};
	for(auto &x:vec)prefix_sum.push_back(prefix_sum.back()+x);
	while(q--){
		int l,r;cin>>l>>r;
		cout<<prefix_sum[r]-prefix_sum[l-1]<<"\n";
	}
}

signed main(){
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	solve();
}