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

vector<string> vecThree = {"MMM", "CCC", "XXX", "III", "MCM", "CXC", "XIX"};
vector<string> vecTwo = {"MM", "CC", "XX", "II"};

bool isThreePal(string s){
  return find(vecThree.begin(), vecThree.end(), s) != vecThree.end();
}

bool isTwoPal(string s){
  return find(vecTwo.begin(), vecTwo.end(), s) != vecTwo.end();
}

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
    int n;
    cin >> n;
    string s;
    cin >> s;
    vector<string> ans;
    int i = 0;
    for(; i < n - 2; i++){
      if(isThreePal(s.substr(i, 3))){
        ans.push_back(s.substr(i, 3));
        i += 2;
      }else if(isTwoPal(s.substr(i, 2))){
        if(isThreePal(s.substr(i + 1, 3))){
          ans.push_back(s.substr(i, 1));
        }else{
          ans.push_back(s.substr(i, 2));
          i++;
        }
      }else{
        ans.push_back(s.substr(i, 1));
      }
    }
    if(i == n - 2){
      if(isTwoPal(s.substr(i, 2)))
        ans.push_back(s.substr(i, 2));
      else{
        ans.push_back(s.substr(i, 1));
        ans.push_back(s.substr(i + 1, 1));
      }
    }else if(i == n - 1){
      ans.push_back(s.substr(i, 1));
    }
    cout << ans.size() << '\n';
    for(int i = 0; i < ans.size(); i++){
      cout << ans[i] << '\n';
    }
    return 0;
}