@regress("len(it)","+","a")
def headerSize(fp): pass
from sys import argv; fps = argv[1:]
  
with open(argv[0], "r") as f: headerSize(f.read(), argv[0])
for fp in argv[1:]:
  with open(fp, "r") as f: s = f.read(); code = s[headerSize(s)+1:]
  with open(fp, "w") as f: f.write(code)

def regress(*code_parts):
  code = "".join(code_parts)
  def solve(d, x,y): #不懂算法就写死点二元仅(+)啦
    vL = eval(code_parts[0], None, d)
    for k in d: d[k] = (y - vL)
  def excVar(ex): s = ex.args[0]; return s[len("name "):s.rfind("'")]
  def wrap(whatever): #我也拽下洋文（迫真
    syms = {} #已回归表
    def call(x, y=None):
      syms["it"] = x
      if y != None:
        try: eval(code) if len(syms)==0 else None
        except NameError as ex: syms[excVar(ex)] = None
        solve(syms, x, y)
      return eval(code, None, syms)
    return call
  return wrap