def main():
  from sys import stdin
  input=stdin.readline
  import math
  # n = int(input())
  # s = input()[:-1]
  a,b = map(int, input().split())
  # A = list(map(int, input().split()))
  if a > b:
    a,b = b,a
  if a == b:
    print(a * 2 ** (0.5))
  else:
    print(math.sqrt(b*b - a*a))
main()