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Connect the corners without 4 in a row

Connect opposite corners of a rectangle of characters without putting 4 characters in a row.

## Input
- Two numbers, W and H, representing the width and height of the rectangle
- Each number will be in the range 2 to 70

## Output
- A rectangular grid of characters, of width W and height H
- You may choose any 2 distinct characters to represent path and background
- The output must contain 2 connected path characters in diagonally opposite corners of the grid
  - Connected means there is a path from one to the other moving only between adjacent path characters
  - Adjacent means 1 character away horizontally or vertically (but not both - diagonal adjacency does not count as connection for this challenge)
- The output must not contain 4 adjacent path characters in a line horizontally or vertically
- There is no limit to how many of the characters may be path characters, provided there are never 4 in a row.
  - There may be redundant sections connected to the path
  - There may be disconnected sections of path provided the main path meets the requirements

## Examples

These examples use `#` for a path character and `.` for the background.

### Valid examples for input 4, 3

```text
##..
.##.
..##

.###
.#..
##..

#...
##..
.###

##.#
.###
##.#
```

### Invalid examples for input 4, 3

```text
4 in a line horizontally:

#...
####
...#

Depends on diagonal adjacency, which does not count as connection:

#...
.#..
..##

Does not connect diagonally opposite corners:
###.
..##
###.
```

### Valid examples for input 7, 5

```text
###....
..#....
..###..
....#..
....###

##.....
.##....
..##...
...##..
....###

#......
#......
##.###.
.#.#.##
.###..#

###....
..###..
###.###
#...#.#
###...#
```

### Invalid examples for input 7, 5

```text
Does not connect two diagonally opposite corners:

###....
..###..
....###
...##..
...#...

Has 4 in a row horizontally:

####...
...#...
...###.
.....#.
.....##

Has 4 in a row vertically:

###....
..#....
..#.###
..###.#
......#

Depends on diagonal adjacency, which does not count as connection:

##.....
..##...
....##.
......#
......#
```

## Validator
You can check a specific output using this [path validator](https://trichoplax.github.io/connect-the-corners-validator/), which will give a reason for any failed validations.

> Explanations are optional, but I'm more likely to upvote answers that have one.