#include<bits/stdc++.h>
using namespace std;
map<string,int>f;
const int N=30;
int n,res,cnt[N];
string s[N];
char c;
int check(string s1,string s2){ //判断连接长度
    string now1="",now2="";
    for(int i=s1.size()-1,j=1;i>=0&&j<s2.size();i--,j++){
        now1=s1[i]+now1;
        now2+=s2[j-1];
        if(now1==now2) return j;
    }
    return -1;
}
int dfs(string path){
    if(f.count(path)) return f[path]; //记忆化
    //cout<<path<<endl;
    int res=path.size();  //初始化
    for(int i=1;i<=n;i++){
        if(!cnt[i]) continue;
        int ans=check(path,s[i]);
        if(ans!=-1){
            string last=path;
            path+=s[i].substr(ans);
            cnt[i]--;
            res=max(res,dfs(path));
            cnt[i]++;
            path=last;
        }
    }
    return f[path]=res;
}
int main(){
    cin>>n;
    for(int i=1;i<=n;i++){
        cin>>s[i];
        cnt[i]=2; //记录目前可用数量
    }
    cin>>c;
    for(int i=1;i<=n;i++){
        if(s[i][0]==c){
            for(int j=1;j<=n;j++) cnt[j]=2;
            cnt[i]=1;
            res=max(res,dfs(s[i]));
        }
    }
    cout<<res<<endl;
    return 0;
}