#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
#define REP(i, n) for (int i = 0; i < (n); ++i)
#define REPR(i, n) for (int i = n - 1; i >= 0; --i)
#define FOR(i, m, n) for (int i = m; i < n; ++i)
#define FORR(i, m, n) for (int i = m; i >= n; --i)
#define ALL(v) (v).begin(),(v).end()
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }
const ll INF=1LL<<60;
const int inf=(1<<30)-1;
const int mod=1e9+7;
int dx[8]={1,0,-1,0,-1,-1,1,1};
int dy[8]={0,1,0,-1,-1,1,-1,1};
int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    vector<ll> a(5);
    REP(i,5) cin >> a[i];
    reverse(ALL(a));
    vector<ll> b;
    b.push_back(1);
    b.push_back(1);
    while(b[b.size()-2]+b[b.size()-1]<=1e16){
        ll res=b[b.size()-2]+b[b.size()-1];
        b.push_back(res);
    }
    int ans=0;
    REP(i,b.size()){
        int cnt=0;
        REP(j,5){
            if(i+j>=b.size()) break;
            if(a[j]==b[i+j]) cnt++;
            else break;
        }
        chmax(ans,cnt);
    }
    cout << ans << endl;
}