#include <iostream>
#include <string.h>

using namespace std;

const bool DEBUG{true};

int main(int argc, char * argv[], char * envp[]) {
    if (DEBUG){
        cout << "\tDEBUG: Start the program" << endl;
    }

    string greeting{"Hello World!"};

    if (DEBUG){
        cout << "\tDEBUG: The greeting is " << greeting<< endl;
    }

    for(int i = 0; envp[i] != nullptr; ++i) {
        if (false) {
            cout << "\tDEBUG: i = " << i << " envp[i] = " << envp[i] << endl;
        }

        if (strncmp("SILLY=", envp[i],6) == 0) {
             greeting = "Hi Mars!";
             if (DEBUG) {
                 cout << "\tDEBUG: Got it, changing the greeting to " <<  greeting << endl;
             }
        }
    }

    cout << greeting << endl;

    return 0;
}