/*
    Author : linneszyx
*/

#include <bits/stdc++.h>

using namespace std;

#define int long long int
#define F first
#define S second
#define pb push_back
#define si set<int>
#define vi vector<int>
#define pii pair<int, int>
#define vpi vector<pii>
#define vpp vector<pair<int, pii>>
#define mii map<int, int>
#define mpi map<pii, int>
#define spi set<pii>
#define endl "\n"
#define sz(x) ((int)x.size())
#define all(p) p.begin(), p.end()
#define double long double
#define forn(i, e) for (int i = 0; i < e; i++)
#define forsn(i, s, e) for (int i = s; i < e; i++)
#define rforn(i, s) for (int i = s; i >= 0; i--)
#define rforsn(i, s, e) for (int i = s; i >= e; i--)
#define que_max priority_queue<int>
#define que_min priority_queue<int, vi, greater<int>>
#define fast_cin()                    \
    ios_base::sync_with_stdio(false); \
    cin.tie(NULL);                    \
    cout.tie(NULL)
const int N = 1e5 + 5;
const int mod = 1e9 + 7;
int f(int n)
{
    int s = 0;
    while (n != 1)
    {
        if (n % 2 == 0)
            n /= 2;
        else
            n = 3 * n + 1;
        s++;
        if (s > 50)
        {
            return -1;
        }
    }
    return s;
}
void waiffuu()
{
    int n;
    cin >> n;
    int res = f(n);
    if (res == -1)
    {
        cout << "P(N) does not stop within 50 steps." << endl;
    }
    else
    {
        cout << "Number of stop steps for P(N): " << res << endl;
    }
}

int32_t main()
{
    fast_cin();
#ifndef ONLINE_JUDGE
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
#endif
    int t = 1;
    //	cin >> t;
    while (t--)
        waiffuu();
    return 0;
}