data = {
 "天津":{
  "南開區(qū)":{
   "南開大學(xué)":{
    "歷史系":{},
    "文學(xué)系":{},
    "英語系":{},
   },
   "科技大學(xué)":{
    "計算機系":{},
    "機器系":{},
    "軟件系":{},
   },
   "理工大學(xué)":{
    "數(shù)學(xué)系":{},
    "化學(xué)系":{},
    "物理系":{},
   },
  },
  "武清區(qū)":{
   "武清大學(xué)":{
    "歷史系":{},
    "文學(xué)系":{},
    "英語系":{},
   },
   "武清科技大學(xué)":{
    "計算機系":{},
    "機器系":{},
    "軟件系":{},
   },
   "武清理工大學(xué)":{
    "數(shù)學(xué)系":{},
    "化學(xué)系":{},
    "物理系":{},
   },
  },
  "北辰區(qū)":{
   "北辰大學(xué)":{
    "歷史系":{},
    "文學(xué)系":{},
    "英語系":{},
   },
   "北辰科技大學(xué)":{
    "計算機系":{},
    "機器系":{},
    "軟件系":{},
   },
   "北辰理工大學(xué)":{
    "數(shù)學(xué)系":{},
    "化學(xué)系":{},
    "物理系":{},
   },
  },
 },
 "河北":{
  "保定市": {
   "保定大學(xué)": {
    "歷史系": {},
    "文學(xué)系": {},
    "英語系": {},
   },
   "保定科技大學(xué)": {
    "計算機系": {},
    "機器系": {},
    "軟件系": {},
   },
   "保定理工大學(xué)": {
    "數(shù)學(xué)系": {},
    "化學(xué)系": {},
    "物理系": {},
   },
  },
  "秦皇島": {
   "秦皇島大學(xué)": {
    "歷史系": {},
    "文學(xué)系": {},
    "英語系": {},
   },
   "秦皇島科技大學(xué)": {
    "計算機系": {},
    "機器系": {},
    "軟件系": {},
   },
   "秦皇島理工大學(xué)": {
    "數(shù)學(xué)系": {},
    "化學(xué)系": {},
    "物理系": {},
   },
  },
  "石家莊": {
   "石家莊大學(xué)": {
    "歷史系": {},
    "文學(xué)系": {},
    "英語系": {},
   },
   "石家莊科技大學(xué)": {
    "計算機系": {},
    "機器系": {},
    "軟件系": {},
   },
   "石家莊理工大學(xué)": {
    "數(shù)學(xué)系": {},
    "化學(xué)系": {},
    "物理系": {},
   },
  },
 },
 "河南":{
  "鄭州市": {
   "鄭州大學(xué)": {
    "歷史系": {},
    "文學(xué)系": {},
    "英語系": {},
   },
   "鄭州科技大學(xué)": {
    "計算機系": {},
    "機器系": {},
    "軟件系": {},
   },
   "鄭州理工大學(xué)": {
    "數(shù)學(xué)系": {},
    "化學(xué)系": {},
    "物理系": {},
   },
  },
  "南陽市": {
   "南陽大學(xué)": {
    "歷史系": {},
    "文學(xué)系": {},
    "英語系": {},
   },
   "南陽科技大學(xué)": {
    "計算機系": {},
    "機器系": {},
    "軟件系": {},
   },
   "南陽理工大學(xué)": {
    "數(shù)學(xué)系": {},
    "化學(xué)系": {},
    "物理系": {},
   },
  },
  "登封市": {
   "登封大學(xué)": {
    "歷史系": {},
    "文學(xué)系": {},
    "英語系": {},
   },
   "登封科技大學(xué)": {
    "計算機系": {},
    "機器系": {},
    "軟件系": {},
   },
   "登封理工大學(xué)": {
    "數(shù)學(xué)系": {},
    "化學(xué)系": {},
    "物理系": {},
   },
  },
 },
}
#exit_flag = False
while True:
 for i in data :
  print (i)
 choice = input ("input:")
 if choice in data:
  while True:
   for i2 in data[choice]:
    print (i2)
   choice2 = input("input2:")
   if choice2 in data[choice]:
    while True:
     for i3 in data[choice][choice2]:
      print (i3)
     choice3 = input("input3:")
     if choice3 in data[choice][choice2]:
      for i4 in data[choice][choice2][choice3]:
       print(i4)
      choice4 = input("Press b to return to the previous level:")
      if choice4 == "b":
       pass
      elif choice4 == "q":
       exit ()
     if choice3 == "b":
      break
     elif choice3 == "q":
      exit()
   if choice2 == "b":
    break
   elif choice2 == "q":
    exit()