foo.c: In function 'main':
foo.c:6:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
    6 |  scanf("%4d%2d%2d",&years,&month,&day);
      |  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
foo.c:7:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
    7 |  scanf("%4d%2d%2d",&years2,&month2,&day2);
      |  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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