运行 ID: 19731

Main.cc: In function ‘int main()’:
Main.cc:13:15: error: ‘cout’ was not declared in this scope
     if(a==17) cout<<"13562027";
               ^~~~
Main.cc:13:15: note: suggested alternative:
In file included from Main.cc:1:0:
/usr/include/c++/7/iostream:61:18: note:   ‘std::cout’
   extern ostream cout;  /// Linked to standard output
                  ^~~~
Main.cc:5:7: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%lf",&a);
  ~~~~~^~~~~~~~~~