#include <bits/stdc++.h>

using namespace std;

int n;
vector<string> words;
vector<int> used;
int maxLen = 0;

int getoverlap(const string& a,const string& b)
{
  int len = min(a.size(),b.size());
  for(int l = 1;l<len;++l)
  {
    if(a.substr(a.size()-l) == b.substr(0,l))
    return l;
  }
  return 0;
}
void dfs(string dragon)
{
  maxLen = max(maxLen,(int)dragon.size());
  for(int i = 0;i<n;i++)
  {
    if(used[i]<2)
    {
      int overlap = getoverlap(dragon,words[i]);
      if(overlap > 0 && overlap<min(dragon.size(),words[i].size())){
        used[i]++;
        dfs(dragon+words[i].substr(overlap));
        used[i]--;
      }
    }
  }
}
int main()
{
  cin>>n;
  words.resize(n);
  used.resize(n,0);
  for(int i = 0;i<n;i++)
  {
    cin>>words[i];
  }
  char startChar;
  cin>>startChar;
  for(int i = 0;i<n;i++)
  {
    if(words[i][0] == startChar)
    {
      used[i]++;
      dfs(words[i]);
      used[i]--;
    }
  }
  cout << maxLen << endl;
  return 0;
}