include <stdio.h>

include <math.h>

int main() {

double a, d, c;
scanf("%lf", &a);
if (a > 0) {
	d = sqrt(a);
	printf("%0.5lf", d);
}
if (a < 0) {
	c = a * a;
	printf("%.5lf", c);
}
return 0;

}