local Dict = require("Dictionary")
local Stack = require("Stack")

function add(stack: Stack)
  local a: any =stack:pop()
  local b: any=stack:pop()
  if a is number and b is number then
    local c=a+b
    stack:push(c)
  else
    error("invalid operands for add operation!")
  end
end
function dot(s: Stack)
	print(s:pop())
end