micro-bit Stopwatch

let CountingDown = false
let counter = 0
input.onButtonPressed(Button.A, () => {
    counter += 1
})
input.onButtonPressed(Button.B, () => {
    CountingDown = true
})
counter = 3
CountingDown = false
basic.forever(() => {
    basic.showNumber(counter)
    if (CountingDown == true) {
        basic.pause(1000)
        counter += -1
        if (counter <= 0) {
            CountingDown = false
            basic.pause(100)
            basic.showLeds(`
                . . . . .
                . . . . .
                . . . . .
                . . . . .
                . . . . .
                `)
            basic.pause(100)
            basic.showLeds(`
                . # # . .
                # . . # .
                # . . # .
                # . . # .
                . # # . .
                `)
            basic.pause(100)
            basic.showLeds(`
                . . . . .
                . . . . .
                . . . . .
                . . . . .
                . . . . .
                `)
            basic.pause(100)
            basic.showLeds(`
                . # # . .
                # . . # .
                # . . # .
                # . . # .
                . # # . .
                `)
            basic.pause(100)
            basic.showLeds(`
                . . . . .
                . . . . .
                . . . . .
                . . . . .
                . . . . .
                `)
            basic.pause(100)
            basic.showLeds(`
                . # # . .
                # . . # .
                # . . # .
                # . . # .
                . # # . .
                `)
        }
    }
})