#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
int main() {
    ll a[5];
    for (int i = 0; i < 5; i++) {
        cin >> a[i];
    }
    ll F[80]{};
    F[0] = 0;
    F[1] = 1;
    for (int i = 2; i < 80; i++) {
        F[i] = F[i - 1] + F[i - 2];
    }
    int ans = 0;
    for (int i = 0; i < 74; i++) {
        int t = 0;
        for (int j = 4; j >= 0; j--) {
            if (a[j] != F[i + 4- j]) break;
            t++;
        }
        ans = max(ans, t);
    }
    cout << ans << "\n";
    return 0;
}