///G. Hagopian
/// PPP18 ex 5

/** Write a function,
string cat_dot(const string& s1, const string& s2),
that concatenates two strings with a dot in between.
For example, cat_dot("Niels", "Bohr") will return a
string containing Niels.Bohr.*/

#include<iostream>
using namespace std;

string cat_dot(const string& s1, const string& s2) {
    return s1+'.'+s2;
}

int main() {
    string s1{"cat"};
    string s2{"dog"};
    cout << cat_dot(s1,s2);
}