#include<iostream>
using namespace std;

long long n;

long long get(long long x)
{
    long long res = x;
    while(x != 1)
    {
        x % 2 ? x = 3 * x + 1 : x /= 2;
        if(x > res) res = x;
    }
    return res;
}

int main()
{
    cin >> n;

    long long res = 1;
    long long t;
    if(n > 2)
    {
        long long i = n / 2; //从n的一半开始枚举
        if(i % 2 == 0) i++; //如果n的一半是偶数，加1变成奇数，只有奇数才会增大，更有可能找到最大值
        for(; i <= n; i += 2)
        {
            t = get(i);
            if(t > res) res = t;
        }
    }
    else res = n;

    cout << res;
    return 0;
}