1 const int base[6][6] = { {0, 1, 2, 3, 4, 5}, {1, 0, 3, 2, 5, 4},
 2                    {2, 0, 1, 4, 5, 3}, {3, 0, 4, 1, 5, 2},
 3                    {4, 0, 2, 3, 5, 1}, {5, 1, 3, 2, 4, 0}};
 4 const int convert[4][6] = { {0, 1, 2, 3, 4, 5}, {0, 2, 4, 1, 3, 5},
 5                       {0, 4, 3, 2, 1, 5}, {0, 3, 1, 4, 2, 5}};
 6
 7 void getDice(int n, int *dice) {
 8     int x = n >> 2, y = n & 3;
 9     REP(i, 6) dice[i] = base[x][convert[y][i]];
10 }
11
12 int st[4][6], mini, curID, dice[4][6];
13 map<string, int> id;
14
15 int getID(char *s) {
16     return id.find(s) == id.end() ? id[s] = curID++ : id[s];
17 }
18
19 void input(int n) {
20     char buf[25];
21     curID = 0;
22     id.clear();
23     REP(i, n) REP(j, 6) {
24         scanf("%s", buf);
25         dice[i][j] = getID(buf);
26     }
27 }
28
29 int stat[24];
30
31 int cal(int n) {
32     int ret = 0;
33     REP(i, 6) {
34         int mx = 0;
35         _clr(stat);
36         REP(j, n) {
37             stat[dice[j][st[j][i]]]++;
38             mx = max(mx, stat[dice[j][st[j][i]]]);
39         }
40         ret += n - mx;
41         if (ret >= mini) return inf;
42     }
43     return ret;
44 }
45
46 void dfs(int n, int p) {
47     if (p >= n) {
48         mini = min(mini, cal(n));
49         return ;
50     }
51     REP(i, 24) {
52         getDice(i, st[p]);
53         dfs(n, p + 1);
54     }
55 }
56
57 int work(int n) {
58     mini = inf;
59     getDice(0, st[0]);
60     dfs(n, 1);
61     return mini;
62 }
63
64 int main() {
65 //    freopen("in", "r", stdin);
66     int n;
67     while (~scanf("%d", &n) && n) {
68         input(n);
69         printf("%d\n", work(n));
70     }
71     return 0;
72 }