Double Click

AtCoder

IDabc297_a

Time2000ms

Memory256MB

Difficulty—

Takahashi turned on a computer at time $0$ and clicked the mouse $N$ times. The $i$\-th $(1 \le i \le N)$ click was at time $T_i$. If he consecutively clicked the mouse at time $x_1$ and time $x_2$ (where $x_1 < x_2$), a double click is said to be fired at time $x_2$ if and only if $x_2 - x_1 \le D$. What time was a double click fired for the first time? If no double click was fired, print `-1` instead. ## Constraints * $1 \le N \le 100$ * $1 \le D \le 10^9$ * $1 \le T_i \le 10^9(1 \le i \le N)$ * $T_i < T_{i+1}(1 \le i \le N-1)$ * All values in the input are integers. ## Input The input is given from Standard Input in the following format: $N$ $D$ $T_1$ $T_2$ $\dots$ $T_N$ [samples]

Samples

Input #1

4 500
300 900 1300 1700

Output #1

1300

Takahashi clicked the mouse at time $900$ and $1300$. Since $1300 - 900 \le 500$, a double click was fired at time $1300$.
A double click had not been fired before time $1300$, so $1300$ should be printed.

Input #2

5 99
100 200 300 400 500

Output #2

\-1

No double click was fired, so print `-1`.

Input #3

4 500
100 600 1100 1600

Output #3

600

If multiple double clicks were fired, be sure to print only the first such event.

API Response (JSON)

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      "content": "Takahashi turned on a computer at time $0$ and clicked the mouse $N$ times. The $i$\\-th $(1 \\le i \\le N)$ click was at time $T_i$.\nIf he consecutively clicked the mouse at time $x_1$ and time $x_2$ (w...",
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Full JSON Raw Segments