1681B - Card Trick - CodeForces Solution

#include <iostream>
#include<bits/stdc++.h>
using namespace std;
#define sort(v) sort(v.begin(),v.end())
#define ll long long

ll mod=1e9+7;
ll power(ll a,ll b){
  if(a==0)return 1;
  ll ans=power(a/2,b);
  ans*=ans;
  ans%=mod;
  if(a%2)ans*=b;
  ans%=mod;
  return ans;
}

ll mul(ll a,ll b){
  return ((a%mod)*(b%mod))%mod;
}


int main(){
int t;
cin>>t;
while(t--){
  int n;
  cin>>n;
  vector<ll> v(n);
  for(int i=0;i<n;i++)cin>>v[i];

  int m;
  ll s=0;
  cin>>m;
  for(int i=0;i<m;i++){
    ll x;
    cin>>x;
    s+=x;
  }
  s=s%n;
  cout<<v[s]<<endl;
}
  return 0;
}