let
    var = do
            $FP +
    end,

    putendl = 
        (10 putchar),

    fact =
        fn(n: %int) -> %int do
            get %int

            let acc = (1 var) in
                1 acc=
                while (n@) do
                    n@ acc@ * acc=
                    n dec
                end
                acc@
            end

            dump %int
        end,
in
    5 fact putnum putendl
end