foo.cc: In function 'int main()':
foo.cc:14:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   14 |  scanf("%d%d",&a,&b);int i,j,k;
      |  ~~~~~^~~~~~~~~~~~~~
foo.cc:17:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   17 |   scanf("%d%d",&c,&d);
      |   ~~~~~^~~~~~~~~~~~~~

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