foo.c: In function 'main':
foo.c:14:9: warning: 'd' may be used uninitialized [-Wmaybe-uninitialized]
   14 |         printf("%d\n",d);
      |         ^~~~~~~~~~~~~~~~
foo.c:5:17: note: 'd' was declared here
    5 |         int a,c,d;
      |                 ^

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