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

int main() {  
	string first;
    first = "Day";
    first += "number";
    cout << "\nfirst = " << first << endl;
    
    string second;
    second = std::string("abc") + "def";		// This won't compile
    cout << "\nsecond = " << second << endl;
    return 0;
}