It was 2 or 14. One pair of each unclean animal. Seven pairs of each clean animal. The answer is found in Genesis 7:
Take with you seven pairs of every kind of clean animal, a male and its mate, and one pair of every kind of unclean animal, a male and its mate, and also seven pairs of every kind of bird, male and female, to keep their various kinds alive throughout the earth.
Genesis 7:2-3, NIV
Clean animals are okay to eat, such as deer, cows, goats, and sheep. For example, Noah would have had seven pairs of sheep on the ark. Unclean animals are not okay to eat, such as pigs, lizards, horses, and snakes. There would have been a male and female of these.
See Leviticus 11 for a longer list of the clean and unclean animals:
“‘There are some that only chew the cud or only have a divided hoof, but you must not eat them. The camel, though it chews the cud, does not have a divided hoof; it is ceremonially unclean for you. The hyrax, though it chews the cud, does not have a divided hoof; it is unclean for you. The rabbit, though it chews the cud, does not have a divided hoof; it is unclean for you. And the pig, though it has a divided hoof, does not chew the cud; it is unclean for you. You must not eat their meat or touch their carcasses; they are unclean for you….
Leviticus 11:4-8, 13-19, 29-31 NIV
“‘These are the birds you are to regard as unclean and not eat because they are unclean: the eagle, the vulture, the black vulture, the red kite, any kind of black kite, any kind of raven, the horned owl, the screech owl, the gull, any kind of hawk, the little owl, the cormorant, the great owl, the white owl, the desert owl, the osprey, the stork, any kind of heron, the hoopoe and the bat….
Of the animals that move along the ground, these are unclean for you: the weasel, the rat, any kind of great lizard, the gecko, the monitor lizard, the wall lizard, the skink and the chameleon. Of all those that move along the ground, these are unclean for you…
While Leviticus 11:4 does not mention sheep by name, it gives this rule for mammals: “Whatever parts the hoof and is cloven-footed and chews the cud, among the animals, you may eat.” Sheep fit this description as they chew the cud and have split hooves.
Deuteronomy 14 also goes over the clean and unclean meat details and mentions some animals by name:
These are the animals you may eat: the ox, the sheep, the goat, the deer, the gazelle, the roe deer, the wild goat, the ibex, the antelope and the mountain sheep. You may eat any animal that has a divided hoof and that chews the cud.
Deuteronomy 14:4-6 NIV