fn balanced(text: Span<u8>) -> Bool {
    var depth: i32 = 0
    var i: usize = 0
    while i < std.mem.len(text) {
        if text[i] == 91 {
            depth = depth + 1
        }
        if text[i] == 93 {
            depth = depth - 1
        }
        if depth < 0 {
            return false
        }
        i = i + 1
    }
    return depth == 0
}

pub fn main(world: World) -> Void raises {
    if balanced(std.mem.span("[[][]]")) && balanced(std.mem.span("[][]")) && (!balanced(std.mem.span("[]][[]")) && !balanced(std.mem.span("][]["))) {
        check world.out.write("balanced brackets ok\n")
    }
}