#include <bits/stdc++.h>
using namespace std;
const int N=1e5+5;
int n,tp,b[N],dp[N],pr[N],z[N];char a[N];map<string,bool> ok;
int f(char x)
{
	if(x=='M') return 1;
	if(x=='C' || x=='D') return 2;
	if(x=='X' || x=='L') return 3;
	if(x=='I' || x=='V') return 4;
	return 0;
}
bool chk(int l,int r)
{
	for(int i=l;i<=r;++i) if(a[i]!=a[l+r-i]) return 0;
	b[l-1]=0;for(int i=l;i<=r;++i) b[i]=max(b[i-1],f(a[i]));
	for(int i=l,t=l;i<=r;++i) if(i==r || b[i]<b[i+1])
	{if(!ok.count(string(a+t,a+i+1))) return 0;t=i+1;}return 1;
}
int main()
{
	ok["M"]=ok["MM"]=ok["MMM"]=1;
	ok["C"]=ok["CC"]=ok["CCC"]=ok["CD"]=ok["D"]=ok["DC"]=ok["DCC"]=ok["DCCC"]=ok["CM"]=1;
	ok["X"]=ok["XX"]=ok["XXX"]=ok["XL"]=ok["L"]=ok["LX"]=ok["LXX"]=ok["LXXX"]=ok["XC"]=1;
	ok["I"]=ok["II"]=ok["III"]=ok["IV"]=ok["V"]=ok["VI"]=ok["VII"]=ok["VIII"]=ok["IX"]=1;
	scanf("%d %s",&n,a+1);
	for(int i=1;i<=n;++i)
	{
		dp[i]=1e9;
		for(int j=1;j<=min(i,20);++j) if(chk(i-j+1,i))
		{if(dp[i]>dp[i-j]+1) dp[i]=dp[i-j]+1,pr[i]=i-j;}
	}
	printf("%d\n",dp[n]);
	for(int i=n;i;i=pr[i]) z[++tp]=i;
	reverse(z+1,z+tp+1);
	for(int i=1;i<=tp;++i,putchar('\n'))
		for(int j=z[i-1]+1;j<=z[i];++j) putchar(a[j]);
}