Problem9333--ABC299 —— B - Trick Taking

9333: ABC299 —— B - Trick Taking

[Creator : ]
Time Limit : 1.000 sec  Memory Limit : 512 MiB

Description

$N$ players with ID numbers $1, 2, \ldots, N$ are playing a card game.  
Each player plays one card.

Each card has two parameters: color and rank, both of which are represented by positive integers.  
For $i = 1, 2, \ldots, N$, the card played by player $i$ has a color $C_i$ and a rank $R_i$. All of $R_1, R_2, \ldots, R_N$ are different.

Among the $N$ players, one winner is decided as follows.

-   If one or more cards with the color $T$ are played, the player who has played the card with the greatest rank among those cards is the winner.
-   If no card with the color $T$ is played, the player who has played the card with the greatest rank among the cards with the color of the card played by player $1$ is the winner. (Note that player $1$ may win.)

Print the ID number of the winner.

Input

### Input

The input is given from Standard Input in the following format:

```
$N$ $T$
$C_1$ $C_2$ $\ldots$ $C_N$
$R_1$ $R_2$ $\ldots$ $R_N$
```

Output

### Output

Print the answer.

Constraints

### Constraints

-   $2 \leq N \leq 2 \times 10^5$
-   $1 \leq T \leq 10^9$
-   $1 \leq C_i \leq 10^9$
-   $1 \leq R_i \leq 10^9$
-   $i \neq j \implies R_i \neq R_j$
-   All values in the input are integers.

Sample 1 Input

4 2
1 2 1 2
6 3 4 5

Sample 1 Output

4
Cards with the color 2 are played. Thus, the winner is player 4, who has played the card with the greatest rank, 5, among those cards.

Sample 2 Input

4 2
1 3 1 4
6 3 4 5

Sample 2 Output

1
No card with the color 2 is played. Thus, the winner is player 1, who has played the card with the greatest rank, 6, among the cards with the color of the card played by player 1 (color 1).

Sample 3 Input

2 1000000000
1000000000 1
1 1000000000

Sample 3 Output

1

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