#include<bits/stdc++.h>
using namespace std;
#define int long long

signed main(){
	int n;
	cin >> n;
	vector<string> r(n);
	for(int i = 0; i < n; i++)cin >> r[i];

	int ans = 0;

	for(int i = 0; i < n; i++){
		int sum = 0;
		for(int j = 0; j < r[i].length(); j++){
			if(r[i][j] == 'I'){
				if(j < n - 1){
					if(r[i][j + 1] == 'V'){
						sum += 4;
						j++;
					}else if(r[i][j + 1] == 'X'){
						sum += 9;
						j++;
					}else sum++;
				}else{
					sum++;
				}
			}else if(r[i][j] == 'X'){
				if(j < n - 1){
					if(r[i][j + 1] == 'L'){
						sum += 40;
						j++;
					}else if(r[i][j + 1] == 'C'){
						sum += 90;
						j++;
					}else sum += 10;
				}else{
					sum += 10;
				}
			}else if(r[i][j] == 'C'){
				if(j < n - 1){
					if(r[i][j + 1] == 'D'){
						sum += 400;
						j++;
					}else if(r[i][j + 1] == 'M'){
						sum += 900;
						j++;
					}else sum += 100;
				}else{
					sum += 100;
				}
			}else if(r[i][j] == 'V')sum += 5;
			else if(r[i][j] == 'L')sum += 50;
			else if(r[i][j] == 'D')sum += 500;
			else sum += 1000;
		}
		ans += sum;
		cerr << sum << endl;
	}
	

	string hundred[] = {"C", "CC", "CCC", "CD", "D", "DC", "DCC", "DCCC", "CM"};
	string ten[] = {"X", "XX", "XXX", "XL", "L", "LX", "LXX", "LXXX", "XC"};
	string one[] = {"I", "II", "III", "IV", "V", "VI", "VII", "VIII", "XI"};

	if(ans >= 4000)cout << "ERROR" << endl;
	else{
		int a = ans / 1000;
		if(a != 0)for(int i = 0; i < a; i++)cout << 'M';
		
		ans %= 1000;
		a = ans / 100;
		if(a != 0)cout << hundred[a - 1];

		ans %= 100;
		a = ans / 10;
		if(a != 0)cout << ten[a - 1];

		a = ans % 10;
		if(a != 0)cout << one[a - 1] << endl;
	}
}