# -*- coding: utf-8 -*-
"""
No.419 直角三角形
https://yukicoder.me/problems/no/419

"""
import sys
from sys import stdin
input = stdin.readline


def solve(a, b):
    if a == b:
        return (a**2 + b**2)**0.5
    else:
        if b > a:
            a, b = b, a
        return (a**2 - b**2)**0.5


def main(args):
    a, b = map(int, input().split())
    ans = solve(a, b)
    print(ans)


if __name__ == '__main__':
    main(sys.argv[1:])