{"problem":{"name":"Double Click","description":{"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 $T_i$. If he consecutively clicked the mouse at time $x_1$ and time $x_2$ (w","description_type":"Markdown"},"platform":"AtCoder","limit":{"time_limit":2000,"memory_limit":262144},"difficulty":"None","is_remote":true,"is_sync":true,"sync_url":null,"sign":"abc297_a"},"statements":[{"statement_type":"Markdown","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 $x_2$ (where $x_1 < x_2$), a double click is said to be fired at time $x_2$ if and only if $x_2 - x_1 \\le D$.\nWhat time was a double click fired for the first time? If no double click was fired, print `-1` instead.\n\n## Constraints\n\n*   $1 \\le N \\le 100$\n*   $1 \\le D \\le 10^9$\n*   $1 \\le T_i \\le 10^9(1 \\le i \\le N)$\n*   $T_i < T_{i+1}(1 \\le i \\le N-1)$\n*   All values in the input are integers.\n\n## Input\n\nThe input is given from Standard Input in the following format:\n\n$N$ $D$\n$T_1$ $T_2$ $\\dots$ $T_N$\n\n[samples]","is_translate":false,"language":"English"}],"meta":{"iden":"abc297_a","tags":[],"sample_group":[["4 500\n300 900 1300 1700","1300\n\nTakahashi clicked the mouse at time $900$ and $1300$. Since $1300 - 900 \\le 500$, a double click was fired at time $1300$.\nA double click had not been fired before time $1300$, so $1300$ should be printed."],["5 99\n100 200 300 400 500","\\-1\n\nNo double click was fired, so print `-1`."],["4 500\n100 600 1100 1600","600\n\nIf multiple double clicks were fired, be sure to print only the first such event."]],"created_at":"2026-03-03 11:01:14"}}