foo.cc: In function 'int main()':
foo.cc:16:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf( "%d%d", &n, &num ); 
     ~~~~~^~~~~~~~~~~~~~~~~~~~
foo.cc:22:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
             scanf( "%d", &num ); 
             ~~~~~^~~~~~~~~~~~~~
foo.cc:31:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
             scanf( "%d", &num ); 
             ~~~~~^~~~~~~~~~~~~~

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