foo.c: In function 'main':
foo.c:24:15: warning: format '%ld' expects argument of type 'long int', but argument 2 has type 'int' [-Wformat=]
   24 |     printf("%ld ", gcd(aa, bb));
      |             ~~^    ~~~~~~~~~~~
      |               |    |
      |               |    int
      |               long int
      |             %d
foo.c: In function 'gcd':
foo.c:17:1: warning: control reaches end of non-void function [-Wreturn-type]
   17 | }
      | ^

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