#include <bits/stdc++.h>

using i64 = long long;
using u64 = unsigned long long;
using u32 = unsigned;

using u128 = unsigned __int128;
using i128 = __int128;

int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);

    int N;
    std::cin >> N;
    if (N == 1) {
        std::cout << 3 << '\n';
        return 0;
    }

    bool f = true;
    int cnt = 0;
    std::set<int> s;
    while (N != 1) {
        cnt++;
        if (N & 1) N = 3 * N + 1;
        else N /= 2;
        if (s.count(N)) {
            f = false;
            break;
        }
        s.insert(N);
    }

    if (f) std::cout << cnt << '\n';
    else std::cout << "infinity\n";

    return 0;
}