-- �����Z
-- http://blog.so-net.ne.jp/rainyday/2007-07-16

function table.copy(t)
  local t2 = {}
  for k,v in pairs(t) do
    t2[k] = v
  end
  return t2
end

function enum(items, enums, n)
  if n == 0 then
      coroutine.yield(enums)
  else
    for i,v in ipairs(items) do
      local lenums = table.copy(enums)
      table.insert(lenums, v)
      enum(items, lenums, n-1)
    end
  end
end

function make_expr(ops)
  local expr = ""
  for i,v in ipairs(ops) do
    expr = expr .. i .. v
  end
  return expr .. (table.getn(ops)+1)
end

function gen_expr(ops, n)
  local co = coroutine.create(function() enum(ops, {}, n) end)
  return function()
    local code, res = coroutine.resume(co)
    return res and make_expr(res)
  end
end

i=0
for e in gen_expr({"+", "-", "*", "/", ""}, 8) do
  local result = loadstring("return "..e)()
  if result == 100 then
    print(e.."="..result)
    i = i + 1
  end
end
print(i.." patterns found")