main: Int
main = nth_prime 77

nth_prime: Int -> Int
nth_prime n =
	if n == 1
		then 2
		else nth_prime_helper (n - 1) 3

nth_prime_helper: Int, Int -> Int
nth_prime_helper remaining_primes next_to_try =
	if is_prime next_to_try
		then
			if remaining_primes < 2
				then next_to_try
				else nth_prime_helper (remaining_primes - 1) (next_to_try + 2)
		else nth_prime_helper remaining_primes (next_to_try + 2)

is_prime: Int -> Int
is_prime x =
	if x % 2 == 0
		then 0
		else is_prime_helper x 3

is_prime_helper: Int, Int -> Int
is_prime_helper x try =
	if try * try > x
		then 1
	else if x % try == 0
		then 0
		else is_prime_helper x (try + 2)