using System;
class Program {
	const int MAX = 1048577;
	static int[] cache = new int[MAX];

	static int collatz(ulong n) {
		return collatz(n, 0, 0);
	}
	static int collatz(ulong n, ulong org_n) {
		return collatz(n, org_n, 0);
	}
	static int collatz(ulong n, ulong org_n, int depth) {
		if(MAX > n) {
			if(cache[n] != -1) {
				cache[org_n] = cache[n] + depth;
				return cache[n] + depth;
			}
		}

		if(n % 2 == 0) {
			return collatz(n / 2, org_n, depth + 1);
		} else if(n == 1) {
			cache[org_n] = depth;
			return depth;
		} else {
			return collatz(n * 3 + 1, org_n, depth + 1);
		}
	}


	static void Main() {
		long tick = DateTime.Now.Ticks;
		for(int i = 0; i < MAX; i++)
			cache[i] = -1;

		ulong max_n = 0;
		int max_steps = 0;

		for(ulong i = 1; i < MAX; i++) {
			int steps = collatz(i, i);
			if(max_steps < steps) {
				max_steps = steps;
				max_n = i;
			}
		}

		Console.WriteLine("f(" + max_n + ")=" + max_steps);
		Console.WriteLine((DateTime.Now.Ticks - tick) / 10000L + "ms");
		Console.ReadLine();
	}
}