import java.io.BufferedWriter;
import java.io.File;
import java.io.FileWriter;
import java.io.IOException;

public class KnightMain {

    static int getnewx(int oldx, int rand) {
        int newx = oldx;
        switch (rand) {
        case 0: // NNE
            newx += 1;
            break;
        case 1: // NE
            newx += 2;
            break;
        case 2: // SE
            newx += 2;
            break;
        case 3: // SSE
            newx += 1;
            break;
        case 4: // SSW
            newx -= 1;
            break;
        case 5: // SW
            newx -= 2;
            break;
        case 6: // NW
            newx -= 2;
            break;
        case 7: // NNW
            newx -= 1;
            break;
        default:
            ;
        }
        return newx;
    }

    static int getnewy(int oldy, int rand) {
        int newy = oldy;
        switch (rand) {
        case 0: // NNE
            newy -= 2;
            break;
        case 1: // NE
            newy -= 1;
            break;
        case 2: // SE
            newy += 1;
            break;
        case 3: // SSE
            newy += 2;
            break;
        case 4: // SSW
            newy += 2;
            break;
        case 5: // SW
            newy += 1;
            break;
        case 6: // NW
            newy -= 1;
            break;
        case 7: // NNW
            newy += 2;
            break;
        default:
            ;
        }
        return newy;
    }

    public static void main(String[] args) throws IOException {

        File f = new File("/home/matze/knight.csv");
        BufferedWriter bw = new BufferedWriter(new FileWriter(f));
        long sum = 0;
        for (int i = 0; i < 1000000; i++) {
            int x = 0;
            int y = 0;
            int rand = 0;
            int movecounter = 0;
            do {// move until starting position

                while (true) { // make valid random move
                    double drand = Math.random() * 8;
                    rand = (int) Math.floor(drand);
                    int newx = getnewx(x, rand);
                    int newy = getnewy(y, rand);
                    if (newx >= 0 && newx < 8 && newy >= 0 && newy < 8) {
                        x = newx;
                        y = newy;
                        break;
                    }
                }
                movecounter++;
            } while (x != 0 && y != 0);
            bw.write(i+"," + movecounter);
            bw.newLine();
            sum += movecounter;
        }
        bw.close();
        System.out.println(sum/1000000.0);
    }

}