There are four towns, numbered 1,2,3 and 4. Also, there are three roads. The i-th road connects different towns a_i and b_i bidirectionally. No two roads connect the same pair of towns. Other than these roads, there is no way to travel between these towns, but any town can be reached from any other town using these roads.

Determine if we can visit all the towns by traversing each of the roads exactly once.

Constraints

* 1 \leq a_i,b_i \leq 4(1\leq i\leq 3)
* a_i and b_i are different. (1\leq i\leq 3)
* No two roads connect the same pair of towns.
* Any town can be reached from any other town using the roads.

Input

Input is given from Standard Input in the following format:


a_1 b_1
a_2 b_2
a_3 b_3


Output

If we can visit all the towns by traversing each of the roads exactly once, print `YES`; otherwise, print `NO`.

Examples

Input

4 2
1 3
2 3


Output

YES


Input

3 2
2 4
1 2


Output

NO


Input

2 1
3 2
4 3


Output

YES
// 作者：杨成瑞先生
import java.io.*;
import java.util.*;

public class Main {

	static class FastScanner {
        BufferedReader br;
        StringTokenizer st;

        public FastScanner() {
            try {
                br = new BufferedReader(new InputStreamReader(System.in));
                st = new StringTokenizer(br.readLine());
            } catch (Exception e){e.printStackTrace();}
        }

        public String next() {
            if (st.hasMoreTokens()) return st.nextToken();
            try {st = new StringTokenizer(br.readLine());}
            catch (Exception e) {e.printStackTrace();}
            return st.nextToken();
        }

        public int nextInt() {return Integer.parseInt(next());}

        public long nextLong() {return Long.parseLong(next());}

        public double nextDouble() {return Double.parseDouble(next());}

        public String nextLine() {
            String line = "";
            if(st.hasMoreTokens()) line = st.nextToken();
            else try {return br.readLine();}catch(IOException e){e.printStackTrace();}
            while(st.hasMoreTokens()) line += " "+st.nextToken();
            return line;
        }
    }

    static ArrayList<Integer>[] adj;
    static boolean[] visited;

    public static void dfs(int v) {
        visited[v] = true;
        for(int next : adj[v]) {
            if(!visited[next]) {
                dfs(next);
                break;
            }
        }
    }

	public static void main(String[] args) {
        FastScanner sc = new FastScanner();
        PrintWriter pw = new PrintWriter(System.out);

        adj = new ArrayList[4];
        for(int i=0;i<4;i++) {
            adj[i] = new ArrayList<Integer>();
        }

        for(int i=0;i<3;i++) {
            int a = sc.nextInt() - 1;
            int b = sc.nextInt() - 1;
            adj[a].add(b);
            adj[b].add(a);
        }

        visited = new boolean[4];
        dfs(0);
        //pw.println(Arrays.toString(visited));

        for(int i=0;i<4;i++) {
            if(!visited[i]) {
                pw.println("NO");
                pw.close();
                return;
            }
        }
        pw.println("YES");
        pw.close();
	}

}