import java.io.InputStream;
import java.io.PrintWriter;
import java.lang.reflect.Array;
import java.math.BigDecimal;
import java.util.ArrayDeque;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.PriorityQueue;
import java.util.Queue;
import java.util.Scanner;
import java.util.Set;
import java.util.Stack;
import java.util.TreeMap;
import java.util.TreeSet;

import static java.util.Comparator.*;

public class Main {
    public static void main(String[] args) {
        PrintWriter out = new PrintWriter(System.out);
        Solver solver = new Solver(System.in, out);
        solver.solve();
        out.close();
    }
}
class Solver {
	Scanner sc;
	PrintWriter out;
    public Solver(InputStream in, PrintWriter out) {
    	sc = new Scanner(in);
    	this.out = out;
    }
    // ==================================================================
    public void solve() {
    	long[] A = new long[5];
    	for (int i = 4; i >= 0; i--) {
			A[i] = Long.parseLong(sc.next());
		}
    	long[] f = new long[100];
    	f[0] = f[1] = 1;
    	for (int i = 2; i < 100; i++) {
			f[i] = f[i-1] + f[i-2];
		}
    	int ans = 0, cnt;
//    	for (int i = 0; i < 5; i++) {
    		for (int j = 0; j < 100; j++) {
        		cnt = 0;
				if(f[j] == A[0]) {
					cnt++;
					for (int j2 = 1; j2 < 5; j2++) {
						if(f[j+j2] == A[j2])	cnt++;
						else					break;
					}
					ans = Math.max(ans, cnt);
//					break;
				}
    		}
//    	}
    	out.println(ans);
    }
}