> For the complete documentation index, see [llms.txt](https://trizen.gitbook.io/sidef-lang/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://trizen.gitbook.io/sidef-lang/programming_tasks/n/number_reversal_game.md).

# Number reversal game

```ruby
var turn = 0
var jumble = @(1..9).bshuffle        # best-shuffle

for (turn; jumble != 1..9; ++turn) {
    printf("%2d: %s - Flip how many digits ? ", turn, jumble.join(' '))
    var d = read(Number) \\ break
    jumble[0 .. d-1] = [jumble[0 .. d-1]].reverse...
}

print "    #{jumble.join(' ')}\n"
print "You won in #{turn} turns.\n"
```