#define _CRT_SECURE_NO_WARNINGS
// #define _GLIBCXX_DEBUG
#include <bits/stdc++.h>
using namespace std;
template<class T> ostream &operator << (ostream &os, const vector<T> &);
template<size_t n, class...T> typename enable_if<(n>=sizeof...(T))>::type _ot(ostream &, const tuple<T...> &){}
template<size_t n, class...T> typename enable_if<(n< sizeof...(T))>::type _ot(ostream &os, const tuple<T...> &t){
    os << (n == 0 ? "" : " ") << get<n>(t); _ot<n+1>(os, t);
}
template<class...T> ostream &operator << (ostream &os, const tuple<T...> &t){
    _ot<0>(os, t); return os;
}
template<class T, class U> ostream & operator << (ostream &os, const pair<T,U> &p){
    return os << "(" << p.first << ", " << p.second << ") ";
}
template<class T> ostream &operator << (ostream &os, const vector<T> &v){
    for(size_t i = 0; i < v.size(); i++) os << v[i] << (i + 1 == v.size() ? "" : ", "); return os;
}
#ifdef DEBUG
#define dump(...) (cerr << #__VA_ARGS__ << " = " << make_tuple(__VA_ARGS__) \
                   << " (L : " << __LINE__ << ")" << endl)
#else
#define dump(...)
#endif
#define all(c) begin(c), end(c)
#define range(i,a,b) for(int i = a; i < (int)(b); i++)
#define rep(i,b) range(i,0,b)
#define pb push_back
#define eb emplace_back
#define mp make_pair
#define mt make_tuple
typedef long long ll;
// #define int ll
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int,int> pii;
void fastios(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
}
int const mod = 1000000007;
auto const inf = numeric_limits<int>::max()/8;

ll solve(ll n, ll m){
    vector<ll> a(3);
    a[1] = a[2] = 1;
    while((int)a.size()-1 < n) a.pb(a[a.size()-1] + a[a.size()-2]);
    ll d = a.back() - m;
    int ans = 0;
    for(int i = a.size()-1; i >= 1; i--){
        if(d >= a[i]){
            d -= a[i];
            ans ++;
        }
    }
    if(d) return -1;
    return ans;
}

int main(){
    ll n,m;
    while(cin >> n >> m){
        cout << solve(n,m) << endl;
    }
}