import sys
from math import sqrt

def debug(x, table):
    for name, val in table.items():
        if x is val:
            print('DEBUG:{} -> {}'.format(name, val), file=sys.stderr)
            return None

def solve():
    a, b = map(int, input().split())

    if a > b:
        a, b = b, a

    if a == b:
        ans = sqrt(a**2 + b**2)
    else:
        ans = sqrt(b**2 - a**2)

    print(ans)

if __name__ == '__main__':
    solve()