foo.cc: In function 'int main()':
foo.cc:8:12: warning: unused variable 'T' [-Wunused-variable]
    8 |     int n, T;
      |            ^
foo.cc:11:11: warning: ignoring return value of 'int system(const char*)', declared with attribute warn_unused_result [-Wunused-result]
   11 |     system("pause");
      |     ~~~~~~^~~~~~~~~

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