import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

public class Sample120 {
	private final long maxIndex_;
	private final Map<Long, Long> memo = new HashMap<Long, Long>();

	public Sample120(int max) {
		long maxInd = 0;
		long maxLen = 0;
		List<Long> sequence = new ArrayList<Long>();
		for (long index = 1; index <= max; index++) {
			sequence.clear();
			long len = calc3n1(index, 0, sequence);
			createMemo(len, sequence);
			if (maxLen < len) {
				maxLen = len;
				maxInd = index;
			}
		}
		maxIndex_ = maxInd;
	}
	private long calc3n1(long x, long length, List<Long> sequence) {
		sequence.add(x);
		if (x == 1) return length;

		Long longVal = memo.get(x);
		if (longVal != null) return length + longVal.longValue();

		if ((x & 1) == 0) {
			return calc3n1(x / 2, length + 1, sequence);
		} else {
			return calc3n1(3 * x + 1, length + 1, sequence);
		}
	}
	private void createMemo(long length, List<Long> sequence) {
		long len = length;
		for (int index = 0, max = sequence.size(); index < max; index++) {
			Long longVal = sequence.get(index);
			if (memo.get(longVal) == null) {
				memo.put(longVal, len--);
			}
		}
	}

	public long getMaxIndex() {
		return maxIndex_;
	}
	public long getMaxLength() {
		return memo.get(maxIndex_);
	}


	public static void main(String[] args) {
		long start = System.currentTimeMillis();

		Sample120 instance = new Sample120((int)Math.pow(2, 20));
		System.out.println(instance.getMaxIndex() + ":" + instance.getMaxLength());

		long end = System.currentTimeMillis();
		System.out.println("elapse: " + (end - start) + "(ms)");
	}
}