/*

*/
#include<bits/stdc++.h>
using namespace std;
#define double long double
#define lowbit(x) (x&(-x))
string s1[] = {"M","MM","MMM",""};
string s2[] = {"C","CC","CCC","CD","D","DC","DCC","DCCC","CM",""};
string s3[] = {"X","XX","XXX","XL","L","LX","LXX","LXXX","XC",""};
string s4[] = {"I","II","III","IV","V","VI","VII","VIII","IX",""};
vector<string>t;
char s[100005];int n;
int dp[100005],pre[100005];
signed main(){
	ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
	cin >> n;for(int i = 1;i<=n;i++)cin >> s[i];
	for(int i =0;i<4;i++){
		for(int j =0;j<10;j++){
			for(int k =0;k<10;k++){
				for(int l =0;l<10;l++){
					string s = s1[i]+s2[j]+s3[k]+s4[l];
					int ok  =1;
					for(int p =0;p<s.size();p++)if(s[s.size()-1-p] != s[p])ok = 0;
					if(ok)t.push_back(s); 
				} 
			}
		}
	}
	for(int i = 1;i<=n;i++)dp[i] = n;dp[0]  =0;
	for(int i = 1;i<=n;i++){
		dp[i] = dp[i-1]+1,pre[i] =i-1;
		if(i>=2){
			string s1;s1+=s[i-1],s1+=s[i];
			if(find(t.begin(),t.end(),s1)!=t.end()){
				if(dp[i-2]+1<dp[i]){
					dp[i] = dp[i-2]+1,pre[i] =i-2;
				}
			}
		}
		if(i>=3){
			string s2;s2+=s[i-2],s2+=s[i-1],s2+=s[i];
			if(find(t.begin(),t.end(),s2)!=t.end()){
				if(dp[i-3]+1<dp[i]){
					dp[i] = dp[i-3]+1,pre[i] = i-3;
				}
			}
		}
		
	}
	cout <<dp[n] << '\n';
	vector<string>res;
	int now = n;
	while(now!=0){
		string c;
		for(int i = pre[now]+1;i<=now;i++)c+=s[i];
		now = pre[now];
		res.push_back(c);
	}
	reverse(res.begin(),res.end());
	for(auto x:res)cout << x << '\n';
//	for(auto x:t)cout << " "<< x << endl;
	return 0;
}
/*
10
MMMCMXIXVV
*/