#include <iostream>
#include <cstdlib>
#include <string>   //for class string
using namespace std;

//Convert an integer to a Roman numeral.

int main()
{
	cout << "Please input an integer in the range 1 to 3999 inclusive: ";
	int number {0};
	cin >> number;       //if user inputs 1234, will become 234, 34, 4

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

	if (number < 1 || number > 3999) {
		cerr << "Sorry, " << number << " is out of range.\n";
		return EXIT_FAILURE;
	}

	string a[][10] {
		{"", "M", "MM", "MMM"                                      }, //thousands
		{"", "C", "CC", "CCC", "CD", "D", "DC", "DCC", "DCCC", "CM"}, //hundreds
		{"", "X", "XX", "XXX", "XL", "L", "LX", "LXX", "LXXX", "XC"}, //tens
		{"", "I", "II", "III", "IV", "V", "VI", "VII", "VIII", "IX"}  //ones
	};
	int n {size(a)};  //number of rows

	int power {1000};           //will become 100, 10, 1

	for (int row {0}; row < n; ++row) {   //row is in range 0 to 3 inclusive
		int col {number/power};       //col is in range 0 to 9 inclusive
		cout << a[row][col];
		number %= power;    //means number = number % power
		power /= 10;        //means power = power / 10
	}

	cout << "\n";
	return EXIT_SUCCESS;
}