import java.util.Random;
import java.util.Scanner;

public class Rumors
{
	private final static Random rand = new Random();

	private static int pickIndex(int size, int notA, int notB)
	{
		int idx;
		do {
			idx = rand.nextInt(size);
		} while(idx == notA || idx == notB);
		return idx;
	}

	public static void main(String[] args)
	{
		for(int n = 3; n <= 10; ++n){
			boolean[] people = new boolean [ n ];

			final int T = 10000;
			int total = 0;
			int totalComplete = 0;
			for(int t = 0; t < T; ++t){

				for(int i=0; i<people.length; ++i){
					people[i] = false;
				}

				// pick some place to start (i.e., Bob)
				int current = rand.nextInt(people.length);
				int previous = current;
				people[current] = true;
				int trialTotal = 1;
				total++;

				while(true){
					// pick an index that is not the current person and not the person they heard it from
					int next = pickIndex(people.length, current, previous);

					if(people[next]){
						break;
					}

					// increment the totals
					total++;
					trialTotal++;
					people[next] = true;
					previous = current;
					current = next;
				}
				if(trialTotal == people.length){
					totalComplete++;
				}
			}

			System.out.println(" ===== " + n + " =====");
			System.out.println("average number of people hearing rumor: " + ((double)total) / T);
			System.out.println("probability of all people hearing the rumor: " + ((double)totalComplete)/T);
		}
	}
}