from random import random, randint, choice 


prob = lambda p: random() < p
digit = lambda ds="123456789": choice(ds)
randrange = lambda a, b: range(a, randint(a, b) + 1)
rint = lambda: (
    digit() + "".join("_" if prob(0.25) else digit() for _ in randrange(0, 10))
)
