from fractions import Fraction

def solve(d, nm, nh, vm, vh):
    if vm >= vh: return d / vm
    if nh >= nm: return d / vh
    x = d*(vm + vh) / (2*nm*vm + nh*vh - nh*vm)
    T = nh*x / vh + (d - nh*x) / vm
    return T

while 1:
    d, nm, nh, vm, vh = map(Fraction, input().split())
    if d == 0:
        break
    T = solve(d, nm, nh, vm, vh)
    print('{}/{}'.format(T.numerator, T.denominator))