foo.cc: In function 'int main()':
foo.cc:21:6: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   21 | scanf("%d",&n);n++;
      | ~~~~~^~~~~~~~~
foo.cc:24:6: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   24 | scanf("%lf",&A[i][j]);
      | ~~~~~^~~~~~~~~~~~~~~~

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