text: #include <stdlib.h>
  #include <stdio.h>
  
  #include <matcalc/visitor.h>
  #include <matcalc/collatz.h>
  
  main(int argc, char *argv[]) {
    if(argc != 2)
      return EXIT_FAILURE;
    mpz_t N;
    mpz_inits(N, NULL);
    mpz_set_str(N, argv[1], 10);
    calc_collatz_convergence(N, mpz_printer);
    mpz_clears(N, NULL);
  }
  