cdef extern from "stdlib.h":
  ctypedef int size_t
  void *malloc(size_t size)
  void free(void *ptr)

def cprimes(int kmax):
  cdef int n, k, i
  cdef int *p
  p = <int *>malloc(kmax * sizeof(int))
  result = []
  k = 0
  n = 2
  while k < kmax:
    i = 0
    while i < k and n % p[i] <> 0:
      i = i + 1
    if i == k:
      p[k] = n
      k = k + 1
      result.append(n)
    n = n + 1
  free(<char *>p)
  p = NULL
  return result