foo.c: In function 'main':
foo.c:14:4: warning: suggest explicit braces to avoid ambiguous 'else' [-Wdangling-else]
  if(m==2)
    ^
foo.c:6:5: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d",&y,&m);
     ^~~~~~~~~~~~~~~~~~~

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