#include <iostream>
#include <cmath>
#include <cstring>
#include <cstdlib>
#include <cctype>
using namespace std;

// Create a namespace
namespace mystuff
{
    int cout = 5;
    double sqrt(double x)
    {
        return x / 2.0;
    }
}

int main()
{
    char cout[32] = "This is a bad idea";
    char temp[80];
    std::cout << "hey\n";
    std::cout << "the square root of 2 is " << sqrt(2.) << endl;
    strcpy(temp,"hello");
    strcat(temp," there");
    std::cout << strlen(temp) << temp << endl;
    std::cout << atoi("4") << endl;
    std::cout << toupper('a') << endl;
    std::cout << static_cast<char>(toupper('a')) << endl;

    std::cout << mystuff::cout << ' ' << cout << endl;

    std::cout << sqrt(5.75) << ' ' << mystuff::sqrt(5.75) << endl;
}