#include <cstdio>
#include <algorithm>
#include <utility>
#include <vector>

#define rep(i, j) for(int i = 0; i < j; ++i)

//typedef long long ll

using namespace std;

int main(void){
	int a,b, c,d;
	scanf("%d %d", &a, &b);
	scanf("%d %d", &c, &d);
	int res = (a+b-(c+d));
	res += 30;
	if(res % 2 == 0){
		printf("black\n");
	}
	else
		printf("white\n");
		
	return 0;
}