Nice SubSegments

Let's call arrays of the form x x+1 ... x+k nice. In other words nice arrays are arrays that form increasing arithmetic progression with the difference of one. You are given an array of N integers. Let's denote it's numbers by a1, a2, ..., aN. You are also given M change queries. Every change query is a query of the form "X Y" with the meaning that the X-th number in it becomes equal to Y. We pe