#include<stdio.h>
#include<stdlib.h>
#include<vector>




int even(int x) {
return x%2 == 0;
}

int deven(int x, int y) {
	return even(x) == even(y);
}

int main() {

int x,y;
int xx,yy;

scanf("%d %d", &x,&y);
scanf("%d %d", &xx, &yy);

printf("%s\n", 
(deven(x,y) && (!deven(xx,yy)))
|| (deven(xx,yy) && (!deven(x,y)))
? "white"
: "black"
);





return 0;
}