#include <bits/stdc++.h> 

using namespace std;

#define FOR(i, a, b) for(int i = (a); i < (b); i++)
#define RFOR(i, a, b) for(int i = (a) - 1; i >= (b); i--)
#define SZ(a) int(a.size())
#define ALL(a) a.begin(), a.end()
#define PB push_back
#define MP make_pair
#define F first
#define S second

typedef long long LL;
typedef vector<int> VI;
typedef pair<int, int> PII;
typedef double db;

const int N = 1147;
const int SZ = 11;
const int MOD = (1 << 11) - 1;
db dp[N][1 << SZ];

int n;
int read()
{
	string s;
	cin >> s;
	if(SZ(s) == 2 || ('0' <= s[0] && s[0] <= '9'))
		return stoi(s);
	return 10 + (s == "A");
}
bool hasBit(int mask, int bit)
{
	return (mask >> bit) & 1;
}

void solve()
{
	VI poses;
	int pos;
	cin >> pos;
	pos--;
	poses.PB(pos);
	FOR(i, 0, n)
	{
		poses.PB(poses.back() + read());
	}
	n = poses.back();
	poses.pop_back();
	VI ok(n);
	for(int i : poses)
		ok[i] = 1;
	
	FOR(i, 0, n + 15)
		FOR(mask, 0, 1 << SZ)
			dp[i][mask] = 0;
	dp[n][0] = 1;
	
	RFOR(i, n, 0)
	{
		FOR(mask, 0, 1 << SZ)
		{
			int nmask = (mask << 1) & MOD;
			
			if(ok[i])
			{
				dp[i][nmask + 1] += dp[i + 1][mask];
				continue;
			}
			FOR(move, 2, 12)
			{
				db prob = 1.0 / 13;
				if(move == 10)
					prob *= 4;
				
				dp[i][nmask + hasBit(mask, move - 1)] += dp[i + 1][mask] * prob;
			}
		}
	}
	db ans = 0;
	FOR(i, 0, 10)
	{
		FOR(mask, 0, 1 << SZ)
		{
			if(hasBit(mask, 0))
				ans += dp[i][mask];
		}
	}
	cout << fixed << setprecision(15) << ans / 10 << "\n";
}

int main()
{
	ios::sync_with_stdio(0);
	cin.tie(0);

	while(cin >> n)
		solve();
	
	
	return 0;
}