import java.util.*;

public class Main {
    static final int MOD = 1000000007;
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long[] arr = new long[5];
        for (int i = 4; i >= 0; i--) {
            arr[i] = sc.nextLong();
        }
        long prepre = 1;
        long pre = 1;
        TreeSet<Long> fibo = new TreeSet<>();
        fibo.add(pre);
        while (pre <= 1000000000000000L) {
            long x = pre + prepre;
            fibo.add(x);
            prepre = pre;
            pre = x;
        }
        int ans = 0;
        if (fibo.contains(arr[0])) {
            ans++;
        } else {
            System.out.println(0);
            return;
        }
        int start = 1;
        if (arr[0] == 1 && arr[1] == 1) {
            start++;
            ans++;
        }
        for (int i = start; i < 5; i++) {
            if (fibo.higher(arr[i - 1]) != arr[i]) {
                break;
            }
            ans++;
        }
        System.out.println(ans);
    }
}