import sys
from collections import defaultdict

from typing import List, Tuple


def int1(x: str, /): return int(x) - 1


def input(): return sys.stdin.readline().rstrip('\n')


def dbg(*args, **kwargs):
    print(*(repr(arg) for arg in args), *(f'{k}: {repr(v)}' for k, v in kwargs.items()), sep='; ', file=sys.stderr)


def main():
    a,b,c,d,e,f=map(int, input().split())
    x,y = -c/(2*a),-d/(2*b)
    ar2 = a*x*x+b*y*y+c*x+d*y+e-f
    return (-ar2/a)**0.5


def _start():
    ret = main()

    if ret is not None:
        if isinstance(ret, List) or isinstance(ret, Tuple):
            print(*ret)
        else:
            print(ret)


if __name__ == '__main__':
    _start()