#include <bits/stdc++.h>
#include <iostream>
#include <iomanip>

using namespace std;

#define rep(i, n) for (int i = 0; i < n; i++)
#define sz(x) (long long)(x).size()

string deck;

double dp[78125][25][128];

int fivep[7];

int encode(char c) {
    if (c=='A') return 0;
    if (c=='2') return 1;
    if (c=='3') return 2;
    if (c=='4') return 3;
    if (c=='5') return 4;
    if (c=='6') return 5;
    if (c=='7') return 6;
    return 7;
}

double func(int key, int left, int available) {
    // cout << key << ' ' << left << ' ' << available << endl;
    if (available == 0) return 0;
    if (left < 0) return 0;
    if (dp[key][left][available] == -1) {
        double p = 1;
        double out = 0;
        vector<double> cnt;
        int temp = key;
        double sum = left;
        rep(i, 7) {
            sum+=temp%5;
            cnt.push_back(temp%5);
            temp/=5;
        }
        rep(i, 7) {
            if (cnt[i]==0) continue;
            double pi = cnt[i]/sum;
            int nxtKey = available;
            int curr = i;
            while (curr!=7 and nxtKey & (1<<curr)) {
                nxtKey^=(1<<curr);
                curr = encode(deck[curr]);
            }
            out+=pi*func(key-fivep[i], left, nxtKey);
            p-=pi;
        }
        if (left!=0) out += p * func(key, left-1, available);
        dp[key][left][available] = out+1;
    }
    
    return dp[key][left][available];
}

int main() {
    rep (i, 78125) rep (j, 25) rep (k, 128) {
        dp[i][j][k] = -1;
    }
    cin >> deck;
    fivep[0] = 1;
    rep(i, 6) {
        fivep[i+1]=fivep[i]*5;
    }
    vector<int> cnt(7, 4);
    int extra = 24;
    rep(i, sz(deck)) {
        if (encode(deck[i])!=7) {
            cnt[encode(deck[i])]--;
        }
        else extra--;
    }
    int key = 0;
    rep(i, 7){
        key*=5;
        key+=cnt[6-i];
    }
    cout << fixed << setprecision(10) << func(key, extra, (1<<7)-1) << endl;
}