let n = stdin.ReadLine () |> int

let digits = if n % 36 = 0 then n / 36 - 1 else n / 36
let num = if n % 36 = 0 then 36 else n % 36

let mutable b_head = ""
let mutable n_count = num
for i = 8 downto 1 do
    if b_head = "" && n_count - i <= 0 then
        b_head <- (string (9-i)) + (string (9-i+n_count))
    
    n_count <- n_count - i
    
b_head + String.replicate digits (string b_head.[1]) |> printfn "%s"