foo.cc: In function 'int main()':
foo.cc:6:6: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    6 | scanf("%d",&n);
      | ~~~~~^~~~~~~~~
foo.cc:7:6: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
    7 | scanf("%d%d",&a,&b);
      | ~~~~~^~~~~~~~~~~~~~
foo.cc:12:6: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   12 | scanf("%d%d",&a,&b);
      | ~~~~~^~~~~~~~~~~~~~

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