Contest Duration: ~ (local time)
A - Sushi 2

Time Limit: 1 sec / Memory Limit: 256 MB

### 問題文

E869120 は, AtCoder 回転寿司という店に行った.
この店には, N 個の寿司がある. 寿司にはそれぞれ 1, 2, 3, \cdots, N の番号がつけられている. 寿司 i は, 彼が来店してから a_i+kT 秒後 (k0 以上の整数) のみに取ることができる.

### 入力

N T
a_1 a_2 a_3 ... a_N


### 制約

• N1 以上 100 以下の整数.
• T1 以上 100 以下の整数.
• a_i0 以上 T-1 以下の整数 (1 \leq i \leq N).
• 1 \leq i < j \leq N に対し, a_i \neq a_j.

• N = 1.

• 追加の制約はない.

### 入力例 1

1 6
4


### 出力例 1

4


この場合, 寿司 1 は来店してから 4, 10, 16, 22, 28, \cdots 秒後に取ることができる. 一番早いのは 4 秒後である.

### 入力例 2

3 10
3 7 2


### 出力例 2

12


### 入力例 3

6 15
8 6 9 1 2 0


### 出力例 3

45


### Problem Statement

E869120 went to a famous sushi restaurant: "AtCoder Kuru-kuru Sushi".
In this restaurant, N sushi is being sold. They are conveniently numbered 1 through N. He can pick sushi i at a_i+kT (k is non-negative integer) seconds after he came at "AtCoder Kuru-kuru Sushi". (Note that he can also pick a sushi right after he came)

He want to eat N sushi in ascending order: from sushi 1 to sushi N. In addition, since his eating speed is very fast, he can eat a sushi in 0 second. Moreover, he always eat sushi immediately when he pick a sushi because he is greedy.
How many seconds are needed to eat all sushi in order?

### Input

Input is given from Standard Input in the following format:

N T
a_1 a_2 a_3 ... a_N


### Output

Print the minimum number of seconds to eat all sushi in ascending order.

### Constraints

• 1 \leq N \leq 100
• 1 \leq T \leq 100
• 0 \leq a_i \leq T-1
• a_i \neq a_j (i \neq j)
• All input values are integers.

### Subtasks

Subtask 1 [100 points]

• N = 1

Subtask 2 [100 points]

• There are no additional constraints.

### Sample Input 1

1 6
4


### Sample Output 1

4


He can pick sushi 1 at 4, 10, 16, 22, \cdots seconds after he came at the restaurant.
If he pick sushi 1 at 4 seconds after he came, he can eat all sushi in ascending order in 4 seconds!

### Sample Input 2

3 10
3 7 2


### Sample Output 2

12


He can pick and eat sushi 1 at 3 seconds, sushi 2 at 7 seconds, sushi 3 at 12 seconds after he came at the restaurant.
Also, he can pick sushi 3 at 2 seconds after he came, but because he is greed, he eat the sushi immediately. So to eat sushi in ascending order, it took at least 12 seconds.

### Sample Input 3

6 15
8 6 9 1 2 0


### Sample Output 3

45