#include <cstdio>

int main() {
	int wx,wy,bx,by;
	scanf("%d %d %d %d",&wx,&wy,&bx,&by);
	
	int wcat = 0, bcat = 0;
	
	if ((wx+wy) % 2 == 0) wcat = 1;
	if ((bx+by) % 2 == 0) bcat = 1;
	
	if (wcat == bcat)
		printf("black\n");
	else
		printf("white\n");

	return 0;
}