Description

You are enjoying HS in a galgame, but the game crashes, so you can only do a data structure problem:

Maintain a sequence $a_i$ of length $n$, with $m$ operations.

1. Modify the values in interval $[l,r]$ to $x$.

2. Query how many different numbers appear in interval $[l,r]$. That is, if the same number appears multiple times, it is counted only once.

Input Format

The first line contains two integers $n,m$.

The second line contains $n$ integers representing $a_i$.

The next $m$ lines are either $1\ l\ r\ x$ or $2\ l\ r$, representing modification and query respectively.

Output Format

For each query, output one number as the answer.

5 5
1 2 3 4 5
2 1 5
1 2 3 4
2 1 5
2 3 3
2 2 4

5
3
1
1

Hint

Idea: nzhtl1477, Solution: nzhtl1477, Code: nzhtl1477, Data: nzhtl1477

Constraints: $1\leq n , m \leq 10^5$，$1\leq a_i\leq 10^9$。

Translated by ChatGPT 5