foo.c: In function 'main':
foo.c:21:29: warning: unused variable 'lb' [-Wunused-variable]
   21 |         int la = strlen(a), lb = strlen(b);
      |                             ^~
foo.c:21:13: warning: unused variable 'la' [-Wunused-variable]
   21 |         int la = strlen(a), lb = strlen(b);
      |             ^~

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