#pragma comment(linker, "/STACK:1024000000,1024000000")
#include <cstdio>
#include <string>
#include <cstdlib>
#include <cmath>
#include <iostream>
#include <cstring>
#include <set>
#include <queue>
#include <algorithm>
#include <vector>
#include <map>
#include <cctype>
#include <cmath>
#include <stack>
#define debug() puts("++++");
#define gcd(a, b) __gcd(a, b)
#define lson l,m,rt<<1
#define rson m+1,r,rt<<1|1
#define freopenr freopen("in.txt", "r", stdin)
#define freopenw freopen("out.txt", "w", stdout)
using namespace std;

typedef long long LL;
typedef unsigned long long ULL;
typedef pair<int, int> P;
const int INF = 0x3f3f3f3f;
const double inf = 0x3f3f3f3f3f3f;
const double PI = acos(-1.0);
const double eps = 1e-5;
const int maxn = 20000 + 10;
const int mod = 1e6 + 10;
const int dr[] = {-1, 0, 1, 0};
const int dc[] = {0, 1, 0, -1};
const char *de[] = {"0000", "0001", "0010", "0011", "0100", "0101", "0110", "0111", "1000", "1001", "1010", "1011", "1100", "1101", "1110", "1111"};
int n, m;
const int mon[] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
const int monn[] = {0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
inline bool is_in(int r, int c){
  return r >= 0 && r < n && c >= 0 && c < m;
}
const int dice24[24][6] = {
{2, 1, 5, 0, 4, 3},
{2, 0, 1, 4, 5, 3},
{2, 4, 0, 5, 1, 3},
{2, 5, 4, 1, 0, 3},
{4, 2, 5, 0, 3, 1},
{5, 2, 1, 4, 3, 0},
{1, 2, 0, 5, 3, 4},
{0, 2, 4, 1, 3, 5},
{0, 1, 2, 3, 4, 5},
{4, 0, 2, 3, 5, 1},
{5, 4, 2, 3, 1, 0},
{1, 5, 2, 3, 0, 4},
{5, 1, 3, 2, 4, 0},
{1, 0, 3, 2, 5, 4},
{0, 4, 3, 2, 1, 5},
{4, 5, 3, 2, 0, 1},
{1, 3, 5, 0, 2, 4},
{0, 3, 1, 4, 2, 5},
{4, 3, 0, 5, 2, 1},
{5, 3, 4, 1, 2, 0},
{3, 4, 5, 0, 1, 2},
{3, 5, 1, 4, 0, 2},
{3, 1, 0, 5, 4, 2},
{3, 0, 4, 1, 5, 2},
};

map<string, int> mp;
int dice[10][10];
int ans;
int r[10];

int getId(const string &s){
  if(mp.count(s))  return mp[s];
  return mp[s] = mp.size();
}
int color[10][10];

void judge(){
  for(int i = 0; i < n; ++i)
    for(int j = 0; j < 6; ++j)  color[i][dice24[r[i]][j]] = dice[i][j];
  int tot = 0;
  for(int i = 0; i < 6; ++i){
    int cnt[30];
    memset(cnt, 0, sizeof cnt);
    int mmax = 0;
    for(int j = 0; j < n; ++j)  mmax = max(mmax, ++cnt[color[j][i]]);
    tot += n - mmax;
  }
  ans = min(ans, tot);
}

void dfs(int d){
  if(d == n){ judge();  return ; }
  for(int i = 0; i < 24; ++i){
    r[d] = i;
    dfs(d+1);
  }
}

int main(){
  while(cin >> n && n){
    mp.clear();
    string s;
    for(int i  = 0; i < n; ++i)
      for(int j = 0; j < 6; ++j){
        cin >> s;
        dice[i][j] = getId(s);
      }
      ans = n * 6;
      r[0] = 0;
      dfs(1);
      cout << ans << endl;
  }
  return 0;
}