AT_abc453_b [ABC453B] Sensor Data Logging

In a certain measurement, the sensor readings at times $ 0,1,\dots,T $ are recorded according to the following rules. - At time $ 0 $ , the reading is saved. - At times $ 1,2,\dots,T $ , the reading is saved if and only if the absolute difference between the current reading and the most recently saved reading is at least $ X $ . The sensor reading at time $ i=0,1,\dots,T $ was $ A_i $ . Output the times at which readings were saved and the saved values, in ascending order of time.

The input is given from Standard Input in the following format: > $ T $ $ X $ $ A_0 $ $ A_1 $ $ \dots $ $ A_T $

If $ k $ readings were saved, and the $ i $ -th saved reading in ascending order of time was at time $ t_i $ with value $ a_i $ , output in the following format: > $ t_1 $ $ a_1 $ $ t_2 $ $ a_2 $ $ \vdots $ $ t_k $ $ a_k $

### Sample Explanation 1 The measurement proceeds as follows. - The reading at time $ 0 $ is $ 30 $ . Save it. - The reading at time $ 1 $ is $ 35 $ . The most recently saved reading is $ 30 $ , and the absolute difference is less than $ 10 $ , so it is not saved. - The reading at time $ 2 $ is $ 40 $ . The most recently saved reading is $ 30 $ , and the absolute difference is at least $ 10 $ , so it is saved. - The reading at time $ 3 $ is $ 21 $ . The most recently saved reading is $ 40 $ , and the absolute difference is at least $ 10 $ , so it is saved. - The reading at time $ 4 $ is $ 30 $ . The most recently saved reading is $ 21 $ , and the absolute difference is less than $ 10 $ , so it is not saved. - The reading at time $ 5 $ is $ 12 $ . The most recently saved reading is $ 21 $ , and the absolute difference is less than $ 10 $ , so it is not saved. - The reading at time $ 6 $ is $ 31 $ . The most recently saved reading is $ 21 $ , and the absolute difference is at least $ 10 $ , so it is saved. ### Constraints - $ 1 \le T \le 100 $ - $ 1 \le X \le 100 $ - $ 0 \le A_i \le 100 $ - All input values are integers.