sick: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/sick - from package: clc-intercal

You may install the required package with command apt-get install {package}

Error in other languages:
sick: bevel nie gevind nie
sick: comandă negăsită
sick: comando não encontrado
sick: commande introuvable
sick: command not found
sick: käsku ei ole
sick: không tìm thấy lệnh
sick: komanda nerasta
sick: Kommando nicht gefunden.
sick: kommandot finns inte
sick: komut yok
sick: nie znaleziono polecenia
sick: níor aimsíodh an t-ordú
sick: no se encontró la orden
sick: no s'ha trobat l'ordre
sick: opdracht niet gevonden
sick: parancs nem található
sick: perintah tidak ditemukan
sick: príkaz nenájdený
sick: příkaz nenalezen
sick: команда не найдена
sick: командата не е открита
sick: 命令找不到
sick: コマンドが見つかりません