sub push(x$)
    queue$ = queue$ + x$ + "#"
end sub

sub pop$()
    local i, r$

    if queue$ <> "" then
        i = instr(queue$, "#")
        if i then
            r$ = left$(queue$, i-1)
            stack$ = right$(queue$, len(queue$) - i)
        else
            r$ = queue$
            queue$ = ""
        end if
        return r$
    else
        print "--Queue is empty--"
    end if
end sub

sub empty()
    return queue$ = ""
end sub

// ======== test ========

for n = 3 to 5
    print "Push ", n : push(str$(n))
next

print "Pop ", pop$()

print "Push ", 6 : push(str$(6))

while(not empty())
    print "Pop ", pop$()
wend

print "Pop ", pop$()