from math import sqrt

def sankaku(a, b):
    if a == b:
        ans = sqrt(a**2 + b**2)
        return ans
    else:
        if a > b:
            a, b = b, a
        ans = sqrt(b**2 - a**2)
        return ans

def main():
    a,b = map(int, input().split())
    print(sankaku(a, b))

if __name__ == '__main__':
    main()