import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

a,b = map(int,read().split())

a,b = sorted([a,b])

if a == b:
    c = a * (2 ** .5)
else:
    c = (b * b - a * a) ** .5

print(c)