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

int main ()
{
	cout << "Please input an integer in the range of 1 to 3999 inclusive: ";
	int number {};
	cin >> number;

	if (!cin) {
		cerr << "Sorry, unable to input the integer\n";
		return EXIT_FAILURE;
	}

	if (number < 1 || number >= 4000) {
		 cerr << "Sorry, " << number << " is out of range.\n";
		return EXIT_FAILURE;
	}

	const string thousands[] {"", "M", "MM", "MMM"}; 
	const string hundreds[]  {"", "C", "CC", "CCC", "CD", "D", "DC", "DCC", "DCCC", "CM"};
	const string tens[]	 {"", "X", "XX", "XXX", "XL", "L", "LX", "LXX", "LXXX", "XC"};
	const string ones[]	 {"", "I", "II", "III", "IV", "V", "VI", "VII", "VIII", "IX"};

	int thou {number / 1000};
	int hun  {(number % 1000) / 100};
	int ten  {(number % 100) / 10};
	int one  {number % 10};

	cout << thousands[thou] << hundreds[hun] << tens[ten] << ones[one] << "\n";

	return EXIT_SUCCESS;
}