AT_abc435_e [ABC435E] Cover query

There are $ N $ cells arranged in a row from left to right. The $ i $ -th cell from the left $ (1\leq i\leq N) $ is called cell $ i $ . Initially, all cells are painted white. Process $ Q $ queries in order. The $ i $ -th query $ (1\leq i\leq Q) $ is as follows: > Two integers $ (L_i,R_i) $ $ (1\leq L_i\leq R_i\leq N) $ are given. > Paint all cells $ L_i, L_i+1, \ldots, R_i $ black. > Here, cells that were painted white are now painted black, and cells that were painted black remain as is. > After that, find the number of cells (among the $ N $ cells) that are painted **white**.

The input is given from Standard Input in the following format: > $ N $ $ Q $ $ L_1 $ $ R_1 $ $ L_2 $ $ R_2 $ $ \vdots $ $ L_Q $ $ R_Q $

Output $ Q $ lines. The $ i $ -th line $ (1\leq i\leq Q) $ should contain the answer to the $ i $ -th query.

### Sample Explanation 1 Initially, $ 10 $ cells are arranged in a row from left to right. - The first query paints cells $ 3,4,5 $ black. After the operation, the cells painted white are cells $ 1,2,6,7,8,9,10 $ , which is $ 7 $ cells. - The second query paints cells $ 8,9 $ black. After the operation, the cells painted white are $ 1,2,6,7,10 $ , which is $ 5 $ cells. - The third query paints cells $ 5,6,7,8 $ black. After the operation, the cells painted white are $ 1,2,10 $ , which is $ 3 $ cells. - The fourth query paints cells $ 2,3,\ldots,9 $ black. After the operation, the cells painted white are $ 1,10 $ , which is $ 2 $ cells. - The fifth query paints cell $ 6 $ black. After the operation, the cells painted white are cells $ 1,10 $ , which is $ 2 $ cells. Thus, output $ 7,5,3,2,2 $ in this order on each line. ### Constraints - $ 1\leq N\leq 10^9 $ - $ 1\leq Q\leq 2\times 10^5 $ - $ 1\leq L_i\leq R_i\leq N $ - All input values are integers.