#include <bits/stdc++.h>
#pragma GCC optimize("O3")
using namespace std;
using ll = long long;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define rep2(i,m,n) for (int i = (m); i < (n); ++i)
#define rep3(i,a,b) for (int i = (a); i >= (b); --i)
#define all(x) (x).begin(),(x).end()
inline int popcount(const int x) { return __builtin_popcount(x);}
inline ll popcount(const ll x) { return __builtin_popcountll(x);}
template<class T> void chmin(T &a, const T &b) noexcept { if (b < a) a = b;}
template<class T> void chmax(T &a, const T &b) noexcept { if (a < b) a = b;}
template<class T> void drop(const T &x) { std::cout<<x<<endl; exit(0);}
void debug_out() { std::cout << "\n";}
template<class T, class... Args> void debug_out(const T &x, const Args &... args) { std::cout<<x<< " "; debug_out(args...);}
#ifdef _DEBUG
  #define debug(...) debug_out(__VA_ARGS__)
#else
  #define debug(...) 
#endif

struct InitIO{
  InitIO() {
    std::cin.tie(nullptr);
    std::ios_base::sync_with_stdio(false);
    std::cout << std::fixed << std::setprecision(15);
  }
}init_io;

int main() {
  vector<ll> a(5);
  rep(i, 5) cin >> a[i];
  reverse(all(a));
  vector<ll> dp(80);
  dp[0] = dp[1] = 1;
  rep2(i, 2, 80) dp[i] = dp[i-1] + dp[i-2];
  int ans = 0;
  rep(i, 75) {
    int cnt = 0;
    rep(j, 5) {
      if (a[j] == dp[i+j]) cnt++;
      else break;
    }
    chmax(ans, cnt);
  }
  cout << ans << endl;
  return 0;
}