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

int main() {
	int a, b;
	scanf("%d %d", &a, &b);

	double ans;
	if (a == b) ans = a * sqrt(2.0);
	else {
		int big = a > b ? a : b, small = a < b ? a : b;
		ans = sqrt(big * big - small * small);
	}

	printf("%.7lf\n", ans);
	return 0;
}