#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <functional>
#include <cmath>
#include <iomanip>
#include <stack>
#include <queue>
#include <numeric>
#include <map>
#include <unordered_map>
#include <set>
#include <fstream>
#include <chrono>
#include <random>
#include <bitset>
#define rep(i,n) for(int i=0;i<(n);i++)
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
#define sz(x) ((int)(x).size())
#define pb push_back
#define mod 1000000007
using ll = long long;
using namespace std;
ll gcd(ll a, ll b) {return b?gcd(b,a%b):a;}
ll lcm(ll a, ll b) {return a/gcd(a,b)*b;}

int main(){
  vector<ll> A(5); rep(i,5) cin >> A[i];
  reverse(all(A));
  vector<ll> fib(80,0);
  fib[0] = fib[1] = 1;
  for(int i=2; i<80; i++){
    fib[i] = fib[i-2]+fib[i-1];
  }
  int ans = 0;
  rep(i,sz(fib)){
    int preans = 0;
    if(A[0] == fib[i]){
      rep(j,5){
        if(fib[i+j] == A[j]) {
          preans++;
          if(preans == 5) ans = 5;
        }
        else {
          ans = max(ans,preans);
          break;
        }
      }
    }
  }
  cout << ans << endl;
  return 0;
}