foo.cc: In function 'void operate1()':
foo.cc:55:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   55 |     scanf("%lld%lld%lld", &a, &b, &c); now++;
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
foo.cc: In function 'void operate2()':
foo.cc:59:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   59 |     scanf("%lld%lld", &a, &b);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~
foo.cc: In function 'void operate3()':
foo.cc:63:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   63 |     scanf("%lld%lld%lld", &a, &b, &c);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
foo.cc: In function 'int main()':
foo.cc:68:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   68 |     scanf("%lld%lld", &n, &m);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~
foo.cc:69:39: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   69 |     for (int i = 1; i <= n; i++) scanf("%lld", &w[i]);
      |                                  ~~~~~^~~~~~~~~~~~~~~
foo.cc:73:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   73 |         scanf("%s", opt);
      |         ~~~~~^~~~~~~~~~~
foo.cc:78:29: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   78 |             case 'B' : scanf("%lld", &now); break;
      |                        ~~~~~^~~~~~~~~~~~~~

Found 6 testcases.
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