#include <bits/stdc++.h>

#define REP(i, n) for(int (i)=0;(i)<(n);(i)++)

using namespace std;

int main(){
    int a,b,c,d;
    cin >> a >> b >> c >> d;
    if ((a+b)%2 == (c+d)%2) cout << "black" << endl;
    else cout << "white" << endl;
}