#!/usr/bin/env python
#coding:utf8

import math


def read():
    return map(int, raw_input().split())


def work((a, b)):
    a, b = max(a, b), min(a, b)
    if a != b:
        print "%.10lf" % (math.sqrt(a ** 2 - b ** 2))
    else:
        print "%.10lf" % (math.sqrt(a ** 2 + b ** 2))


if __name__ == "__main__":
    work(read())