#include <stdio.h>
#include <math.h>

int main(void)
{
	float a, b, c, d;
	scanf("%f%f", &a, &b);
	c = a * a - b * b;
	d = b * b - a * a;
	printf("%.7f\n", a != b ? sqrt(c) < sqrt(d) ? sqrt(fabs(c)) : sqrt(fabs(d)) : sqrt(a*b + a * b));
	return 0;
}