#include<bits/stdc++.h>
using i64 = long long;

void solve() {
	int n;
	std::cin >> n;
	std::string s;
	std::cin >> s;
	std::vector<std::string > ans;
	int num = 0;
	std::vector<int> vis(n + 1);
	for (int i = 0; i + 2 < n; i ++) {
		if (s[i] == 'M' && s[i + 1] == 'C' && s[i + 2] == 'M') {
				for (int j = i; j < i + 3; j ++) {
					vis[i] = 1;
				}
				i += 2;
				continue;
			}
			if (s[i] == 'C' && s[i + 1] == 'X' && s[i + 2] == 'C') {
				for (int j = i; j < i + 3; j ++) {
					vis[i] = 1;
				}
				i += 2;
				continue;
			}
			if (s[i] == 'X' && s[i + 1] == 'I' && s[i + 2] == 'X') {
				for (int j = i; j < i + 3; j ++) {
					vis[i] = 1;
				}
				i += 2;
				continue;
			}
	}
 	for (int i = 0; i < n; i ++) {
 		if (i + 2 < n) {
 			if (s[i] == 'M' && s[i + 1] == 'C' && s[i + 2] == 'M') {
 				ans.push_back("MCM");
 				i += 2;
 				continue;
 			}
 			if (s[i] == 'C' && s[i + 1] == 'X' && s[i + 2] == 'C') {
 				ans.push_back("CXC");
 				i += 2;
 				continue;
 			}
 			if (s[i] == 'X' && s[i + 1] == 'I' && s[i + 2] == 'X') {
 				ans.push_back("XIX");
 				i += 2;
 				continue;
 			}
 		}

 		if (s[i] == 'M') {
 			int j = i;
 			std::string t = "";
 			while (j < n && ! vis[j] && j - i < 3 && s[j] == 'M') {
 				t += 'M';
 				j ++;
 			}
 			i = j - 1;
 			ans.push_back(t);
 		} else if (s[i] == 'C') {
 			int j = i;
 			std::string t = "";
 			while (j < n && ! vis[j] && j - i < 3 && s[j] == 'C') {
 				t += 'C';
 				j ++;
 			}
 			i = j - 1;
 			ans.push_back(t);
 		} else if (s[i] == 'D') { 
 			ans.push_back("D");
 		} else if (s[i] == 'X') {
			int j = i;
 			std::string t = "";
 			while (j < n && ! vis[j] && j - i < 3 && s[j] == 'X') {
 				t += 'X';
 				j ++;
 			}
 			i = j - 1;
 			ans.push_back(t);
 		} else if (s[i] == 'L') {
 			ans.push_back("L");
 		} else if (s[i] == 'I') {
			int j = i;
 			std::string t = "";
 			while (j < n && ! vis[j] && j - i < 3 && s[j] == 'I') {
 				t += 'I';
 				j ++;
 			}
 			i = j - 1;
 			ans.push_back(t);
 		} else if (s[i] == 'V') {
 			ans.push_back("V");
 		} 
	}
	std::cout << ans.size() << '\n';
	for (auto it : ans) {
		std::cout << it << '\n';
	}
}
int main() {
	std::ios::sync_with_stdio(false);
	std::cin.tie(nullptr);
	int t = 1;
	//std::cin >> t;
	while (t --) {
		solve();
	}
	return 0;
}