#include<cstdio>

#include<iostream>

#include<cstdlib>

#include<cstring>

#include<algorithm>

#include<queue>

using namespace std;

const int N = 2000, CH = 4;

const int INF = 0x3F3F3F3F;

const char *ACGT = "ACGT";

int Hash[128];

struct trie{

    trie *next[CH];

    trie *fail;

    int cnt, id;

}tree[N];

bool flag[1000];

int chi[1008][4];

class AC_Auto{

    public:

    int nxt;

    trie *root;

    AC_Auto(){

        root = &tree[0];

        nxt=0;

        memset(&tree[0], 0, sizeof(trie));

    }

    void insert(char *s){

        trie *p = root;

        for(int i = 0; s[i]; i++){

            int c = Hash[s[i]];

            if(!p -> next[c]){

                memset(&tree[++nxt], 0, sizeof(trie));

                p -> next[c] = &tree[nxt];

                p -> next[c] -> id = nxt;

            }

            p = p -> next[c];

        }

        p -> cnt = 1;

        flag[p->id] = 1;

    }

    void build(){

        queue<trie *> q;

        q.push(root);

        root -> fail = NULL;

        while(!q.empty()){

            trie *cur = q.front();

            q.pop();

            if(cur -> fail && flag[cur->fail ->id ]){

                flag[cur -> id] = 1;

            }

            for(int i = 0; i < CH; i++){

                trie *son = cur -> next[i];

                trie *tp = (cur == root)? root: cur -> fail->next[i];

                if(son == NULL){

                    cur -> next[i] = tp;

                }else{

                    son -> fail = tp;

                    q.push(son);

                }

                son = cur ->next[i];

                chi[cur -> id][i] = son -> id;

            }

        }

    }

};

char str[1008];

int dp[1008][1000];

int main(){

    Hash['A'] = 0;

    Hash['C'] = 1;

    Hash['G'] = 2;

    Hash['T'] = 3;

    int n;

    int t = 0;

    while(~scanf("%d", &n) && n){

        AC_Auto ac;

        memset(flag, 0, sizeof(flag));

        memset(dp, 0x3F, sizeof(dp));

        for(int i = 0; i < n; i++){

            scanf("%s", str);

            ac.insert(str);

        }

        ac.build();

        dp[0][0] = 0;

        scanf("%s", str);

        int num = ac.nxt + 1;

        int len = 0;

        for(int i = 0; str[i]; i++, len++){

            for(int j = 0; j < num; j++){

                for(int k = 0; k < CH; k++){

                    if(flag[chi[j][k]] == 0){

                        dp[i + 1][chi[j][k]] = min(dp[i + 1][chi[j][k]], dp[i][j] + (ACGT[k] != str[i]));

                    }

                }

            }

        }

        int ans = INF;

        for(int i = 0; i < num ; i++){

            ans = min(ans, dp[len][i]);

        }

        if(ans >= INF){

            ans = -1;

        }

        printf("Case %d: %d\n", ++t, ans);

    }

    return 0;

}