Sequence Operation and Minimum Distance Query

You are given a sequence a₁, a₂, ..., a_n and you need to perform m operations sequentially.

There are two types of operations:

1. Update Operation: Given integers l, r, x, y, for every index i in the range [l, r] (1-indexed) such that a_i = x, change the value to y.

2. Query Operation: Given integers l, r, x, y, find indices i and j (both in the range [l, r]) such that a_i = x and a_j = y while minimizing |i - j|. If a valid pair does not exist, output -1.

   Note: When x = y, if there exists at least one index i in the range with a_i = x, then the minimum |i - i| is 0.

All indices are 1-indexed.

The formulas should be rendered in LaTeX. For example, the sequence is given as \(a_1, a_2, \dots, a_n\) and an update is applied to indices in \([l, r]\).

inputFormat

The first line contains two integers n and m, representing the size of the sequence and the number of operations.

The second line contains n integers, the initial sequence \(a_1, a_2, \dots, a_n\).

The next m lines each describe an operation in one of the following formats:

• For an update operation: 1 l r x y
• For a query operation: 2 l r x y

outputFormat

For each query operation (operation type 2), output the minimum absolute difference \(|i - j|\) found for the specified values in the given range. If no valid pair exists, output -1.

sample

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

1
-1
0
1