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

int main(void) {
	// your code goes here
	int hen1,hen2;
	int temp1,temp2;
	double hen3;

	scanf("%d %d" , &hen1, &hen2);

	temp1 = hen1*hen1 + hen2*hen2;
	temp2 = abs(hen1*hen1 - hen2*hen2);

	if ((temp1 < temp2) || (temp2 == 0)) {
		hen3 = sqrt((double)temp1);
	} else {
		hen3 = sqrt((double)temp2);
	}

	printf("%.10f\n", hen3);

	return 0;
}