#include <iostream>
#include <vector>
#include <algorithm>
#include <atcoder/string>
#include <atcoder/segtree>
using namespace std;
using i32 = int32_t;
using u32 = uint32_t;
using i64 = int64_t;
using u64 = uint64_t;
#define rep(i,n) for(int i=0; i<(n); i++)


int main(){
  int Z = 1000000;
  vector<int> sieve(Z+1,0);
  for(i64 p=2; p<=Z; p++) if(sieve[p] == 0){
    for(i64 i=0; i*p<=Z; i++) sieve[i*p] = sieve[i] + 1;
  }
  
  int N; cin >> N;
  i64 ans = 0;
  rep(i,N){
    int a; cin >> a;
    ans ^= sieve[a];
  }
  if(ans == 0) cout << "black" << endl;
  else cout << "white" << endl;
  return 0;
}

struct ios_do_not_sync{
  ios_do_not_sync(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
  }
} ios_do_not_sync_instance;