#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <cstring>

#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
#include <queue>
#include <stack>
#include <map>
#include <set>

#include <functional>
#include <cassert>

typedef long long ll;
using namespace std;

#define debug(x) cerr << #x << " = " << (x) << endl;


#define mod 1000000007 //1e9+7(prime number)
#define INF 1000000000 //1e9
#define LLINF 2000000000000000000LL //2e18
#define SIZE 100010

//I = 1、V = 5、X = 10、L = 50、C = 100、D = 500、M = 1000

int tonum(string s){
  int sum = 0;
  int n = s.size();
  
  for(int i=0;i<n;i++){
    if(s[i] == 'I'){
      if(i<n-1 && (s[i+1]=='V' || s[i+1]=='X')){
        sum -= 1;
      }else{
        sum += 1;
      }
    }else if(s[i] == 'V'){
      sum += 5;
    }else if(s[i] == 'X'){
      if(i<n-1 && (s[i+1]=='L' || s[i+1]=='C')){
        sum -= 10;
      }else{
        sum += 10;
      }
    }else if(s[i] == 'L'){
      sum += 50;
    }else if(s[i] == 'C'){
      if(i<n-1 && (s[i+1]=='D' || s[i+1]=='M')){
        sum -= 100;
      }else{
        sum += 100;
      }
    }else if(s[i] == 'D'){
      sum += 500;
    }else if(s[i] == 'M'){
      sum += 1000;
    }
  }

  return sum;
}

//I = 1、V = 5、X = 10、L = 50、C = 100、D = 500、M = 1000

string tostr(int num){
  string s[4];

  char a[5] = "IXCM";
  char b[5] = "VLD*";

  for(int i=0;i<4;i++){
    int t = num%10;
    num/=10;

    if(t==4){
      s[i] += a[i]; 
      s[i] += b[i]; 
    }else if(t==9){
      s[i] += a[i]; 
      s[i] += a[i+1]; 
    }else{
      if(t >= 5){
        s[i] += b[i];
      }
      for(int j=0;j<t%5;j++){
        s[i] += a[i];
      }
    }
  }

  return s[3] + s[2] + s[1] + s[0];

}

int main(){
  int n;
  string s;

  int ans = 0;
  
  cin >> n;
  
  for(int i=0;i<n;i++){
    cin >> s;

    ans += tonum(s);
  }

  if(ans >= 4000){
    puts("ERROR");
  }else{
    //debug(ans);
    cout << tostr(ans) << endl;
  }
  
  return 0;
}