#!/usr/bin/env bash

winl=4
win=''

function add() {
  win="${win:1}${1}"
}

function contains() {
  # $1 what
  # $2 where
  local l=${#2}
  local ret=1

  while (( l-- )); do
    [[ "$1" = "${2:$l:1}" ]] && ret=0 && break
  done

  return $ret
}


function unq() {
  local l=${#1}

  while (( --l )); do
    contains ${1:$l:1} ${1:0:$l} && break
  done

  return $l
}

i=$(( $winl - 1 ))

read -n $i win

win=${win:0:1}${win}

while read -n 1 a; do
  let i++
  add $a
  unq "$win" && break
done

echo $i