#include <iostream>
#include <vector>
#include <algorithm>
#include <stack>
#include <queue>
#include <set>
#include <map>
#include <random>
#include <iomanip>
#include <time.h>
#include <bitset>
#include <map>
#include <numeric>
#include <atcoder/modint>
#include <atcoder/dsu>
using namespace atcoder;
using namespace std;
using mint = modint998244353;
#define ll long long
#define pll pair<ll,ll>

ll loop(ll before, ll now, ll idx, ll mod)
{
    if(now==0) return idx;
    else return loop(now, (before+now)%mod, idx+1, mod);
}

ll n;

int main()
{
    cin >> n;
    if(n==1) cout << 1 << endl;
    else cout << loop(1,1,2,n) << endl;
}