public class coinflips {
	public static void main(String[] args) {
		int flips = Integer.parseInt(args[0]);
		int i = 0;
		double flip = 0;
		int heads = 0;
		while (i < flips) {
			flip = Math.random();
			if (flip >= 0.5) {
				heads++;
				System.out.println(heads);
			}
			i++;

		}
		System.out.println((double)(heads) / flips);
	}
}