foo.c: In function 'main':
foo.c:19:4: warning: implicit declaration of function 'exit' [-Wimplicit-function-declaration]
   19 |    exit(1);
      |    ^~~~
foo.c:19:4: warning: incompatible implicit declaration of built-in function 'exit'
foo.c:2:1: note: include '<stdlib.h>' or provide a declaration of 'exit'
    1 | #include <stdio.h>
  +++ |+#include <stdlib.h>
    2 | int pd(int year)
foo.c:24:4: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
   24 |    for(i=1;i<month;i++)
      |    ^~~
foo.c:25:21: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
   25 |       sum=sum+md[i];sum=sum+day;
      |                     ^~~
foo.c:15:4: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   15 |    scanf("%d %d %d",&year,&month,&day);
      |    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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