Package for this problem was not updated by the problem writer or Codeforces administration after we’ve upgraded the judging servers. To adjust the time limit constraint, solution execution time will be multiplied by 2. For example, if your solution works for 400 ms on judging servers, then value 800 ms will be displayed and used to determine the verdict.

Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ACM-ICPC mode for virtual contests.
If you've seen these problems, a virtual contest is not for you - solve these problems in the archive.
If you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.
Never use someone else's code, read the tutorials or communicate with other person during a virtual contest.

No tag edit access

A. Dice Tower

time limit per test

2 secondsmemory limit per test

256 megabytesinput

standard inputoutput

standard outputA dice is a cube, its faces contain distinct integers from 1 to 6 as black points. The sum of numbers at the opposite dice faces always equals 7. Please note that there are only two dice (these dices are mirror of each other) that satisfy the given constraints (both of them are shown on the picture on the left).

Alice and Bob play dice. Alice has built a tower from *n* dice. We know that in this tower the adjacent dice contact with faces with distinct numbers. Bob wants to uniquely identify the numbers written on the faces of all dice, from which the tower is built. Unfortunately, Bob is looking at the tower from the face, and so he does not see all the numbers on the faces. Bob sees the number on the top of the tower and the numbers on the two adjacent sides (on the right side of the picture shown what Bob sees).

Help Bob, tell whether it is possible to uniquely identify the numbers on the faces of all the dice in the tower, or not.

Input

The first line contains a single integer *n* (1 ≤ *n* ≤ 100) — the number of dice in the tower.

The second line contains an integer *x* (1 ≤ *x* ≤ 6) — the number Bob sees at the top of the tower. Next *n* lines contain two space-separated integers each: the *i*-th line contains numbers *a*_{i}, *b*_{i} (1 ≤ *a*_{i}, *b*_{i} ≤ 6; *a*_{i} ≠ *b*_{i}) — the numbers Bob sees on the two sidelong faces of the *i*-th dice in the tower.

Consider the dice in the tower indexed from top to bottom from 1 to *n*. That is, the topmost dice has index 1 (the dice whose top face Bob can see). It is guaranteed that it is possible to make a dice tower that will look as described in the input.

Output

Print "YES" (without the quotes), if it is possible to to uniquely identify the numbers on the faces of all the dice in the tower. If it is impossible, print "NO" (without the quotes).

Examples

Input

3

6

3 2

5 4

2 4

Output

YES

Input

3

3

2 6

4 1

5 3

Output

NO

Codeforces (c) Copyright 2010-2017 Mike Mirzayanov

The only programming contests Web 2.0 platform

Server time: Dec/15/2017 01:33:42 (c4).

Desktop version, switch to mobile version.

User lists

Name |
---|