The contest language is Tcl. Tcl (originally from "Tool Command Language", but conventionally rendered as "Tcl" rather than "TCL"; pronounced as "tickle" or "tee-see-ell") is a scripting language created by John Ousterhout (from Wikipedia article). Here is the sample program which reads and writes a single integer number:
set line [gets stdin]<br> scan $line "%d" n<br> puts $nYou may use "Custom Test" feature (see contest user interface) to run your programs.