С проверкой данных: import fractions, math
def f(x):
intx = int(x)
return intx if intx == x else x
try:
a, b, c = map(fractions.Fraction, input('a b c: ').split())
if a
print(((lambda a,b,c: ((a + b + c) / 2 * ((a + b + c) / 2 - a) * ((a + b + c) / 2 - b) * ((a + b + c) / 2 - c))**0.5)((float(input())),(float(input())),(float(input())))))