I leran a lot about md! wow. This is crom from here .

TypeError: unsupported operand type(s) for *: 'float' and 'NoneType' cr-content   // 百度的 css改变

if __name__ == '__main__':
    # A comment
    print 'hello world'

#include <iostream.h>
use namespace std;
void main()
{
cout<<"hello";
}