#include<iostream>

using namespace std;

int main(int argc, char const *argv[]) {
  int a, b, c, d;
  cin>>a>>b>>c>>d;
  int c1, c2;
  c1 = (a+b)%2;
  c2 = (c+d)%2;
  if(c1 == c2)
    cout<<"black"<<endl;
  else
    cout<<"white"<<endl;
  return 0;
}