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
import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.List;
import java.util.InputMismatchException;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        FastReader in = new FastReader(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TaskB solver = new TaskB();
        solver.solve(1, in, out);
        out.close();
    }

    static class TaskB {
        static boolean ans = false;

        public void solve(int testNumber, FastReader in, PrintWriter out) {
            int n = 4;
            List<Integer>[] g = GraphUtils.nextU(in, n, n - 1, true);
            dfs(g, 0, -1, new boolean[n]);
            out.println(ans ? "YES" : "NO");
        }

        public static void dfs(List<Integer>[] g, int cur, int par, boolean[] marked) {
            if (ans) return;
            marked[cur] = true;
            for (Integer next : g[cur]) {
                if (marked[next]) continue;
                dfs(g, next, cur, marked);
            }
            boolean ok = true;
            for (int i = 0; i < 4; ++i) ok &= marked[i];
            marked[cur] = false;
            if (ok) ans = true;
        }

    }

    static class GraphUtils {
        public static List<Integer>[] nextU(FastReader in, int n, int m, boolean oneIndexed) {
            int diff = oneIndexed ? 1 : 0;
            List<Integer>[] g = new List[n];
            for (int i = 0; i < n; ++i) g[i] = new ArrayList<>();
            for (int i = 0; i < m; ++i) {
                int u = in.nextInt() - diff;
                int v = in.nextInt() - diff;
                g[u].add(v);
                g[v].add(u);
            }
            return g;
        }

    }

    static class FastReader {
        private InputStream stream;
        private byte[] buf = new byte[8192];
        private int curChar;
        private int pnumChars;

        public FastReader(InputStream stream) {
            this.stream = stream;
        }

        private int pread() {
            if (pnumChars == -1) {
                throw new InputMismatchException();
            }
            if (curChar >= pnumChars) {
                curChar = 0;
                try {
                    pnumChars = stream.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException();
                }
                if (pnumChars <= 0) {
                    return -1;
                }
            }
            return buf[curChar++];
        }

        public int nextInt() {
            int c = pread();
            while (isSpaceChar(c))
                c = pread();
            int sgn = 1;
            if (c == '-') {
                sgn = -1;
                c = pread();
            }
            int res = 0;
            do {
                if (c == ',') {
                    c = pread();
                }
                if (c < '0' || c > '9') {
                    throw new InputMismatchException();
                }
                res *= 10;
                res += c - '0';
                c = pread();
            } while (!isSpaceChar(c));
            return res * sgn;
        }

        private boolean isSpaceChar(int c) {
            return c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == -1;
        }

    }
}

