#include<stdio.h>

main() {
	int x, y, f, max, x_max, y_max;

	for(x=-10;x<=10;x++) {
		for(y=-10;y<=10;y++) {
			f = x*x - 9*x*y + y*y;
			if ((x==-10)&&(y==-10)) {
				max = f;
				x_max = x;
				y_max = y;
			} else if (f>max) {
				max = f;
				x_max = x;
				y_max = y;
			}
		}
	}
	printf("El max esta a (%d, %d) = %d\n", x_max, y_max, max);
}