实在找不出哪里错了

def leijia(e,s):
    if e.isdigit() and s.isdigit():
        if e > s:
            t = e
            e = s
            s = t
        sum = 0
        for i in range(e, s + 1):
            sum = sum + i
        return sum
    else:
        print("请用数字开头和结束")

e=input("请输入开头的数字：")
s=input("请输入结尾的数字：")
print(leijia(e,s))


Traceback (most recent call last):
  File "D:/人工智能/课外推荐/9天/函数.py", line 42, in <module>
    print(leijia(e,s))
  File "D:/人工智能/课外推荐/9天/函数.py", line 28, in leijia
    if int(e).isdigit() and int(s).isdigit():
AttributeError: 'int' object has no attribute 'isdigit'