Как Вызвать Созданную Функцию?

#include <iostream>
#include <string>
using namespace std;
string first(string);
string second(string);
 
int main()
{
    
}
string first(string func1)
{
    string text;
    text = "Three blind mice\n";
}
string second (string func2)
{
    string otext;
    otext = "See how they run\n";
}

#include <iostream>
#include <string>
 
using namespace std;
 
//--------------------------------------------------------------------------------------------------
string first();
string second();
//--------------------------------------------------------------------------------------------------
int main()
{
    cout << first();
    cout << second();
 
    system("pause");
    return 0;
}
//--------------------------------------------------------------------------------------------------
string first()
{
    string text;
    text = "Three blind mice\n";
    return text;
}
//--------------------------------------------------------------------------------------------------
string second()
{
    string text;
    text = "See how they run\n";
    return text;
}
//--------------------------------------------------------------------------------------------------

int main()
{
    first("");
    second("");
}