foo.c: In function 'main':
foo.c:16:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   16 |  scanf("%d %d",&b1,&a1);
      |  ^~~~~~~~~~~~~~~~~~~~~~
foo.c:17:2: warning: ignoring return value of 'scanf', declared with attribute warn_unused_result [-Wunused-result]
   17 |  scanf("%d %d",&b2,&a2);
      |  ^~~~~~~~~~~~~~~~~~~~~~

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