// compile: make data
// run: ./data < data.in
#include <bits/stdc++.h>
using namespace std;
#pragma GCC optimize("O3,unroll-loops")
#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#ifdef LOCAL
#include <debug/codeforces.h>
#define debug(x...) _debug_print(#x, x);
#define Debug(x...) _debug_print_format(#x, x);
std::ifstream terminal("/dev/tty");
#define PP cerr<<"\033[1;30mpause...\e[0m",terminal.ignore();
#else
#define debug(x...)
#define Debug(x...)
#define PP
#endif
template<typename...Args> void print_(Args...args){((cout<<args<<" "),...)<<endl;}
#define VI vector<int>
#define VII vector<vector<int>>
#define VIII vector<vector<vector<int>>>
#define rep(i,a,b) for(int i=(a);i<(int)(b);++i)
#define sz(v) ((int)(v).size())
#define print(...) print_(__VA_ARGS__);
#define FIND(a, x) ((find(a.begin(),a.end(),(x))!=a.end())?1:0)
#define cmin(x,...) x=min({(x), __VA_ARGS__})
#define cmax(x,...) x=max({(x), __VA_ARGS__})
#define INTMAX (int)(9223372036854775807)
#define INF (int)(1152921504606846976)
#define NaN (int)(0x8b88e1d0595d51d1)
#define double long double
#define int long long
#define uint unsigned long long
#define MAXN 200010

int32_t main() {
    ios::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);

    int n; cin >> n;
    vector<vector<vector<double>>> p(n+1, vector<vector<double>>(8, vector<double>(8, 0)));
    // rep(i, 0, 8) rep(j, 0, 8) p[0][i][j] = 1;
    p[0][0][0] = 1;
    const pair<int, int> dir[4] = {{1, 0}, {0, 1}, {-1, 0}, {0, -1}};
    vector<vector<double>> res(8, vector<double>(8, 1));
    rep(sx, 0, 8) rep(sy, 0, 8) {
        p.assign(n+1, vector<vector<double>>(8, vector<double>(8, 0)));
        p[0][sx][sy] = 1;
        rep(i, 0, n) {
            rep(x, 0, 8) rep(y, 0, 8) {
                int num = 0;
                rep(j, 0, 4) {
                    int nx = x + dir[j].first;
                    int ny = y + dir[j].second;
                    if (nx < 0 || nx >= 8 || ny < 0 || ny >= 8) continue;
                    ++num;
                }
                rep(j, 0, 4) {
                    int nx = x + dir[j].first;
                    int ny = y + dir[j].second;
                    if (nx < 0 || nx >= 8 || ny < 0 || ny >= 8) continue;
                    p[i+1][nx][ny] += p[i][x][y] / num;
                }
            }
        }
        rep(x, 0, 8) rep(y, 0, 8) {
            res[x][y] *= (1 - p[n][x][y]);
        }
    }
    double ans = 0;
    rep(i, 0, 8) rep(j, 0, 8) ans += res[i][j];
    cout << fixed << setprecision(6) << ans << endl;

    return 0;
}