import java.util.*;
import java.util.concurrent.*;

public class Euler352 {
    static double T(int s, double p) {
        if (s <= 0)
            return 0.0;
        if (s == 1)
            return 1.0;

        double q = 1.0 - p;
        double[] qpow = new double[s + 1];
        qpow[0] = 1.0;
        for (int i = 1; i <= s; ++i) {
            qpow[i] = qpow[i - 1] * q;
        }

        double[] A = new double[s + 1];
        double[] B = new double[s + 1];
        A[0] = 0.0;
        B[0] = 0.0;
        A[1] = 1.0;
        B[1] = 0.0;

        for (int n = 2; n <= s; ++n) {
            double pe = 1.0 - qpow[n];
            double bestB = 1e100;
            for (int k = 1; k < n; ++k) {
                double pa = qpow[k] * (1.0 - qpow[n - k]) / pe;
                double pb = 1.0 - pa;
                double cost = 1.0 + pa * B[n - k] + pb * (B[k] + A[n - k]);
                if (cost < bestB)
                    bestB = cost;
            }
            B[n] = bestB;

            double bestA = 1.0 + (1.0 - qpow[n]) * B[n];
            for (int k = 1; k < n; ++k) {
                double cost = 1.0 + A[n - k] + (1.0 - qpow[k]) * B[k];
                if (cost < bestA)
                    bestA = cost;
            }
            A[n] = bestA;
        }
        return A[s];
    }

    public static String solve() {
        int threads = Runtime.getRuntime().availableProcessors();
        if (threads == 0)
            threads = 1;

        ExecutorService executor = Executors.newFixedThreadPool(threads);
        List<Future<Double>> futures = new ArrayList<>();

        for (int i = 1; i <= 50; i++) {
            final int p_idx = i;
            futures.add(executor.submit(() -> {
                double p = p_idx / 100.0;
                return T(10000, p);
            }));
        }

        double total = 0.0;
        try {
            for (Future<Double> f : futures) {
                total += f.get();
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        executor.shutdown();

        return String.format(Locale.US, "%.6f", total);
    }

    public static void main(String[] args) {
        System.out.println(solve());
    }
}