#include <iostream>
#include <iomanip>
#include <cstdlib>
#include <string>
#include <iterator>   // for size()

using namespace std;

static const char* ordinal(int n) {
    switch (n) {
        case 1: return "st";
        case 2: return "nd";
        case 3: return "rd";
        default: return "th";
    }
}

int main()
{
    const string a[] {
        "",                           // dummy element (index 0)
        "partridge in a pear tree.",  // 1
        "turtle doves",               // 2
        "French hens",                // 3
        "calling birds",              // 4
        "gold rings",                 // 5
        "geese a-laying",             // 6
        "swans a-swimming",           // 7
        "maids a-milking",            // 8
        "ladies dancing",             // 9
        "lords a-leaping",            // 10
        "pipers piping",              // 11
        "drummers drumming"           // 12
    };

    const size_t ndays {size(a) - 1};

    for (size_t day {1}; day <= ndays; ++day) {
        cout << "On the " << day << ordinal(day)
             << " day of Christmas\n"
             << "My true love gave to me\n";

        for (size_t gift {day}; gift >= 1; --gift) {
            if (gift > 1) {
                cout << setw(2) << gift << " " << a[gift] << "\n";
            } else if (day == 1) {
                cout << "A " << a[gift] << "\n";
            } else {
                cout << "And a " << a[gift] << "\n";
            }
            if (gift == 1) break; // prevent wraparound on size_t underflow
        }

        cout << "\n";
    }

    return EXIT_SUCCESS;
}