Score : $200$ points

Problem Statement

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.

4 2
1 3
2 3

YES

We can visit all the towns in the order $1,3,2,4$.

3 2
2 4
1 2

NO

2 1
3 2
4 3

YES