foo.c: In function 'er':
foo.c:25:9: warning: function returns address of local variable [-Wreturn-local-addr]
   25 |  return a;
      |         ^
foo.c: In function 'main':
foo.c:7:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
    7 |  scanf("%d",&x);
      |  ^~~~~~~~~~~~~~

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