import sys; input = sys.stdin.buffer.readline
sys.setrecursionlimit(10**7)
from collections import defaultdict
con = 10 ** 9 + 7; INF = float("inf")

def getlist():
	return list(map(int, input().split()))

#処理内容
def main():
	a, b = getlist()
	if a == b:
		print(a * (2 ** 0.5))
		return
	a, b = list(sorted([a, b]))
	ans = (b ** 2 - a ** 2) ** 0.5
	print(ans)


if __name__ == '__main__':
	main()