A game consists of $n$ rooms and $m$ teleporters. At the beginning of each day, you start in room $1$ and you have to reach room $n$ .

You can use each teleporter at most once during the game. You want to play the game for exactly $k$ days. Every time you use any teleporter you have to pay one coin. What is the minimum number of coins you have to pay during $k$ days if you play optimally?

The first input line has three integers $n$ , $m$ and $k$ : the number of rooms, the number of teleporters and the number of days you play the game. The rooms are numbered $1,2,\dots,n$ .

After this, there are $m$ lines describing the teleporters. Each line has two integers $a$ and $b$ : there is a teleporter from room $a$ to room $b$ .

There are no two teleporters whose starting and ending room are the same.

• $2 \le n \le 500$
• $1 \le m \le 1000$
• $1 \le k \le n-1$
• $1 \le a,b \le n$

First print one integer: the minimum number of coins you have to pay if you play optimally. Then, print $k$ route descriptions according to the example. You can print any valid solution.

If it is not possible to play the game for $k$ days, print only -1.