#include<iostream>
#include<string>
#include<vector>
#include<algorithm>
#include<bitset>
#include<set>
#include<map>
#include<stack>
#include<queue>
#include<deque>
#include<list>
#include<iomanip>
#include<cmath>
#include<cstring>
#include<functional>
#include<cstdio>
#include<cstdlib>
#include<unordered_map>
#include<unordered_set>
using namespace std;

#define repr(i, a, b) for (int i = (int)(a); i < (int)(b); i++)
#define rep(i, n) repr(i, 0, n)
#define INF 2e9
#define MOD 1000000007
//#define MOD 998244353
#define LINF (long long)4e18
#define jck 3.141592
#define PI acos(-1.0);

const double EPS = 1e-10;

using ll = long long;
using Pi = pair<int,int>;
using Pl = pair<ll,ll>;



int main(){
    ll fibo[10000000];
    fibo[0] = 1;
    fibo[1] = 1;
    repr(i,2,80){
        fibo[i] = fibo[i-1]+fibo[i-2];
    }
    vector<ll> v(5);
    rep(i,5) cin >> v[i];
    reverse(v.begin(),v.end());
    if(v[0] == 1){
        int k1[] = {1,1,2,3,5};
        int k2[] = {1,2,3,5,8};
        int ans = 0;
        int now = 1;
        repr(i,1,5){
            if(v[i] != k1[i]) break;
            now++;
        }
        ans = max(ans,now);
        now = 1;
        repr(i,1,5){
            if(v[i] != k2[i]) break;
            now++;
        }
        ans = max(ans,now);
        cout << ans << endl;
        return 0;
    }
    int ans = 0;
    rep(i,80){
        if(fibo[i] == v[0]){
            ans++;
            repr(j,i+1,i+5){
                if(fibo[j] != v[j-i]){
                    cout << ans << endl;
                    return 0;
                }
                ans++;
            }
        }
    }
    cout << ans << endl;
}