foo.cc: In function 'int main()':
foo.cc:4:47: warning: unused variable 'lon' [-Wunused-variable]
     int sum = 0, max = 0, num, n, qm, bj, lw, lon;
                                               ^~~
foo.cc:5:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", &n);
     ~~~~~^~~~~~~~~~
foo.cc:8:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%s", s);
         ~~~~~^~~~~~~~~
foo.cc:9:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d %d ", &qm, &bj);
         ~~~~~^~~~~~~~~~~~~~~~~~~~
foo.cc:10:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%c %c ", &gb, &xb);
         ~~~~~^~~~~~~~~~~~~~~~~~~~
foo.cc:11:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d", &lw);
         ~~~~~^~~~~~~~~~~

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