foo.c: In function 'main':
foo.c:13:9: warning: implicit declaration of function 'sleep' [-Wimplicit-function-declaration]
   13 |         sleep(1)
      |         ^~~~~
foo.c:13:17: error: expected ';' before 'return'
   13 |         sleep(1)
      |                 ^
      |                 ;
   14 |         return 0;
      |         ~~~~~~   

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