#include <bits/stdc++.h>
using ll = long long;
using namespace std;

int main() {
    ll n;
    cin >> n;

    for (int k = 2; k < 64; k++) {
        vector<ll> a(k, 0);
        a.back() = 1;
        for (int i = k;; i++) {
            ll t = 0;
            for (int j = i - k; j < i; j++) {
                t += a[j];
            }
            if (t == n) {
                cout << k << endl;
                exit(0);
            }
            if (t > n) break;
            a.push_back(t);
        }
    }
    cout << -1 << endl;

    return 0;
}