foo.cc: In function 'int main()':
foo.cc:189:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  189 |     scanf("%s",a);
      |     ~~~~~^~~~~~~~
foo.cc:190:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  190 |     scanf("%s",b);
      |     ~~~~~^~~~~~~~

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