use std::io::Read;
const MAX: u64 = 1000000000000000;

fn main() {
    let mut s: String = String::new();
    std::io::stdin().read_to_string(&mut s).ok();
    let mut itr = s.trim().split_whitespace();
    let v: Vec<u64> = (0..5)
        .map(|_| itr.next().unwrap().parse().unwrap())
        .collect();

    let mut f1: u64 = 0;
    let mut f2: u64 = 1;
    let mut fib: Vec<u64> = Vec::new();
    while f2 < MAX * 2 {
        fib.push(f2);
        let tmp = f1;
        f1 = f2;
        f2 += tmp;
    }
    let mut ans: usize = 0;
    let mut i: usize = v.len();
    while i > 0 {
        i -= 1;
        let mut l: usize = 0;
        let mut r: usize = fib.len();
        while r > l + 1 {
            let mid = (l + r) / 2;
            if v[i] < fib[mid] {
                r = mid;
            } else {
                l = mid;
            }
        }
        if v[i] != fib[l] {
            if i == 0 {
                break;
            }
            i -= 1;
            continue;
        }
        if v[i] == 1 {
            l = 0;
        }
        let mut j: usize = i;
        let mut cnt: usize = 0;
        while l < fib.len() && fib[l] == v[j] {
            cnt += 1;
            l += 1;
            if j == 0 {
                break;
            }
            j -= 1;
        }
        ans = std::cmp::max(ans, cnt);
    }
    println!("{}", ans);
}