foo.cc: In function 'int main()':
foo.cc:12:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   12 |  scanf("%d/%d",&a1,&b1);
      |  ~~~~~^~~~~~~~~~~~~~~~~
foo.cc:15:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   15 |   scanf("%d/%d",&a2,&b2);
      |   ~~~~~^~~~~~~~~~~~~~~~~

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