foo.c: In function 'main':
foo.c:17:23: error: 'counter' undeclared (first use in this function); did you mean 'conter'?
   17 |         printf("%d\n",counter);
      |                       ^~~~~~~
      |                       conter
foo.c:17:23: note: each undeclared identifier is reported only once for each function it appears in

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