package yukicoder;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class No518Another {

	static Map<Integer, String> n2r = new HashMap<Integer, String>() {
		{
			put(1, "I");
			put(2, "II");
			put(3, "III");
			put(4, "IV");
			put(5, "V");
			put(6, "VI");
			put(7, "VII");
			put(8, "VIII");
			put(9, "IX");
			put(10, "X");
			put(11, "XI");
			put(13, "XIII");
			put(17, "XVII");
			put(20, "XX");
			put(21, "XXI");
			put(30, "XXX");
			put(33, "XXXIII");
			put(40, "XL");
			put(46, "XLVI");
			put(50, "L");
			put(51, "LI");
			put(60, "LX");
			put(66, "LXVI");
			put(69, "LXIX");
			put(71, "LXXI");
			put(80, "LXXX");
			put(90, "XC");
			put(94, "XCIV");
			put(100, "C");
			put(101, "CI");
			put(128, "CXXVIII");
			put(200, "CC");
			put(201, "CCI");
			put(222, "CCXXII");
			put(256, "CCLVI");
			put(300, "CCC");
			put(316, "CCCXVI");
			put(340, "CCCXL");
			put(400, "CD");
			put(425, "CDXXV");
			put(433, "CDXXXIII");
			put(444, "CDXLIV");
			put(490, "CDXC");
			put(500, "D");
			put(501, "DI");
			put(506, "DVI");
			put(579, "DLXXIX");
			put(600, "DC");
			put(700, "DCC");
			put(743, "DCCXLIII");
			put(800, "DCCC");
			put(900, "CM");
			put(999, "CMXCIX");
			put(1000, "M");
			put(1001, "MI");
			put(1006, "MVI");
			put(1111, "MCXI");
			put(1132, "MCXXXII");
			put(1258, "MCCLVIII");
			put(1300, "MCCC");
			put(1674, "MDCLXXIV");
			put(1844, "MDCCCXLIV");
			put(2000, "MM");
			put(2906, "MMCMVI");
			put(3001, "MMMI");
			put(3998, "MMMCMXCVIII");
		}
	};
	static Map<String, Integer> r2n = new HashMap<String, Integer>() {
		{
			put("I", 1);
			put("II", 2);
			put("III", 3);
			put("IV", 4);
			put("V", 5);
			put("VI", 6);
			put("VII", 7);
			put("VIII", 8);
			put("IX", 9);
			put("X", 10);
			put("XI", 11);
			put("XIII", 13);
			put("XVII", 17);
			put("XX", 20);
			put("XXI", 21);
			put("XXX", 30);
			put("XXXIII", 33);
			put("XL", 40);
			put("XLVI", 46);
			put("L", 50);
			put("LI", 51);
			put("LX", 60);
			put("LXVI", 66);
			put("LXIX", 69);
			put("LXXI", 71);
			put("LXXX", 80);
			put("XC", 90);
			put("XCIV", 94);
			put("C", 100);
			put("CI", 101);
			put("CXXVIII", 128);
			put("CC", 200);
			put("CCI", 201);
			put("CCXXII", 222);
			put("CCLVI", 256);
			put("CCC", 300);
			put("CCCXVI", 316);
			put("CCCXL", 340);
			put("CD", 400);
			put("CDXXV", 425);
			put("CDXXXIII", 433);
			put("CDXLIV", 444);
			put("CDXC", 490);
			put("D", 500);
			put("DI", 501);
			put("DVI", 506);
			put("DLXXIX", 579);
			put("DC", 600);
			put("DCC", 700);
			put("DCCXLIII", 743);
			put("DCCC", 800);
			put("CM", 900);
			put("CMXCIX", 999);
			put("M", 1000);
			put("MI", 1001);
			put("MVI", 1006);
			put("MCXI", 1111);
			put("MCXXXII", 1132);
			put("MCCLVIII", 1258);
			put("MCCC", 1300);
			put("MDCLXXIV", 1674);
			put("MDCCCXLIV", 1844);
			put("MM", 2000);
			put("MMCMVI", 2906);
			put("MMMI", 3001);
			put("MMMCMXCVIII", 3998);
		}
	};

	public static void main(String[] args) throws IOException {
		BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
		in.readLine();
		String romanStr = in.readLine();
		List<String> romans = Arrays.asList(romanStr.split(" "));
		int value = 0;
		for (String roman : romans) {
			value += r2n.get(roman);
		}
		System.out.println(n2r.get(value));
	}
}