Syntax highlight test

Trying to use syntax highlight:
 c++:

        
cpp
        

            
        
     
 #include <iostream>
using namespace std;

int main() 
{
    cout << "Hello, World!";
    return 0;
} 

python:

        
go
        

            
        
     
import matplotlib
k=input()
mylist=[]
mylist.append(k)