foo.c: In function 'S':
foo.c:14:1: warning: control reaches end of non-void function [-Wreturn-type]
   14 | }
      | ^
foo.c: In function 'main':
foo.c:46:9: warning: 'm' may be used uninitialized [-Wmaybe-uninitialized]
   46 |         printf("%d %d",z,m);
      |         ^~~~~~~~~~~~~~~~~~~
foo.c:30:18: note: 'm' was declared here
   30 |         int  n,z,m,i;
      |                  ^
foo.c:46:9: warning: 'z' may be used uninitialized [-Wmaybe-uninitialized]
   46 |         printf("%d %d",z,m);
      |         ^~~~~~~~~~~~~~~~~~~
foo.c:30:16: note: 'z' was declared here
   30 |         int  n,z,m,i;
      |                ^

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