#include <cstdlib>#include <cctype>#include <cstring>#include <cstdio>#include <cmath>#include <algorithm>#include <vector>#include <string>#include <iostream>#include <sstream>#include <map>#include <set>#include <queue>#include <stack>#include <fstream>#include <numeric>#include <iomanip>#include <bitset>#include <list>#include <stdexcept>#include <functional>#include <utility>#include <ctime>using namespace std;typedef long long LL;typedef unsigned long long ULL;#define MAX(a,b) ((a) > (b) ? (a) : (b))#define MIN(a,b) ((a) < (b) ? (a) : (b))#define MEM(a,b) memset((a),(b),sizeof(a))const LL INF = 1e4 + 1;const LL N = 5e4 + 10;const double eps = 1e-11;map<vector<int>, double> mv;vector<string> vs[9];double dfs(vector<int>& v){if (mv.count(v))return mv[v];int cnt = 0;double sum = 0;for (int i = 0; i < v.size(); i++){if (v[i] == 0) continue;for (int j = i + 1; j < v.size(); j++){if (v[j] == 0) continue;if (vs[i][v[i] - 1][0] == vs[j][v[j] - 1][0]){v[i]--;v[j]--;sum += dfs(v);cnt++;v[i]++;v[j]++;}}}if (cnt == 0) return mv[v] = 0;else return mv[v] = sum / cnt;}int main(){for (int i = 0; i < 9; i++) vs[i].resize(4);while (cin >> vs[0][0] >> vs[0][1] >> vs[0][2] >> vs[0][3]){for (int i = 1; i < 9; i++){for (int j = 0; j < 4; j++){cin >> vs[i][j];}}mv.clear();mv[vector<int>(9,0)] = 1;vector<int> v(9, 4);printf("%.9fn", dfs(v));}return 0;}
