I have tried to perform this arithmetic expression from command line but it doesn't give me valid output. How do I perform the expression in the below code using the simplest skills of C++?

```
#include <iostream>
using namespace std;

int main()
{
    cout << " 4 * (1.0 - 1/3 + 1/5 - 1/7 + 1/9 - 1/11) = ";
    return 0;
}

```