what is M and G basis in stock if

M contributes
noncash property FMV: 80,000
liab on property: 50,000
basis of property: 40,000
cash: 20,000

G contributes
noncash property FMV: 70,000
liab on property: 0
basis of property: 50,000
cash: 0
G also received 20,000 cash

I believe M has a basis of $10k as follows:

$40,000 - adj basis of property

+$20,000 - cash contributed

-$50,000 - liability assumed by corporation

=$10,000

I don't see where there is a gain is recognized here because the cash and adj basis of the property is taken into account. The basis is not adjusted to zero (yet).

I believe G has a basis of $30k as follows:

$50,000 - adj basis of property

-$20,000 - cash received

=$30,000