/in/foo.cc: In function 'int main()':
/in/foo.cc:17:22: warning: statement is a reference, not call, to function 'std::ios_base::sync_with_stdio' [-Waddress]
  ios::sync_with_stdio;
                      ^
/in/foo.cc:17:22: warning: statement has no effect [-Wunused-value]