#include <bits/stdc++.h>
using namespace std;

long long memo[10000];

long long fib(int n) {
    if (memo[n] != 0) return memo[n];
    if (n == 0 || n == 1) return memo[n] = 1;
    return memo[n] = fib(n - 1) + fib(n - 2);
}

int main(void) {
    vector<long long> a(5);
    for (int i = 0; i < 5; i++) {
        cin >> a[4 - i];
    }
    fib(100);
    int cnt = 0;
    int ans = 0;
    for (int i = 0; i < 100; i++) {
        if (cnt != 0 && memo[i] != a[cnt]) {
            ans = max(cnt, ans);
            cnt = 0;
        }
        if (a[cnt] == memo[i]) cnt++;
    }
    cout << ans << endl;
    return 0;
}