#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<long long,long long> pll;
#define ep emplace_back
#define pb push_back
#define mp make_pair
#define rep(i,n) for(int i=0;i<(n);++i)
constexpr int mod=1000000007;
constexpr int mod1=998244353;
vector<int> dx={0,1,0,-1},dy={-1,0,1,0};
bool inside(int y,int x,int h,int w){
	if(y<h && y>=0 && x<w && x>=0) return true;
	return false;
}





int main(){
	cin.tie(0);
	ios::sync_with_stdio(false);
	vector<ll> a(5);
	rep(i,5) cin >> a.at(i);
	reverse(a.begin(),a.end());
	vector<ll> dp(100000);
	dp[0] = 1;
	dp[1] = 1;
	int k = 0, ans = 0;
	for(int i = 2; i < 100000; i++){
		dp[i] = dp[i - 1] + dp[i - 2];
		if(dp[i] >= 1e15){
			k = i + 1;
			break;
		}
	}
	rep(i,k){
		int cnt = 0;
		rep(j,5){
			if(a.at(j) == dp[i + j]) cnt++;
			else break;
		}
		ans = max(ans, cnt);
	}
	cout << ans << endl;
}