#define _USE_MATH_DEFINES
#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
#include <queue>
#include <math.h>
#include <cmath>
#include <stack>
#include <map>
#include <set>
#include <numeric>
#include <iomanip>
#include <climits>
#include <functional>
#include <cassert>
#include <tuple>
using namespace std;
using ll = long long;

ll N;

int main() {

    cin >> N;
    for(int k = 2; k < 100; ++k) {
        deque<ll> dq;
        for(ll i = 1; i < 1000; ++i) {
            ll sum = 0;
            if(i < k) continue;
            else if(i == k) sum = 1;
            else {
                for(auto v : dq) sum += v;
            }

            if(sum == N) {
                cout << k << endl;
                return 0;
            } else if(sum > N) {
                if(dq.size() < k) {
                    cout << -1 << endl;
                    return 0;
                } else break;
            }

            dq.push_back(sum);
            if(dq.size() > k) dq.pop_front();
        }
    }

}