def integer(str_x):
for j in str_x:
if j not in '0123456789':
return False
return True


str_ip = input().split('.')
A = str_ip[0]
B = str_ip[1]
C = str_ip[2]
D = str_ip[3]
if integer(A) and integer(B) and integer(C) and integer(D):
if 0 <= int(integer(A)) <= 255 and 0 <= int(integer(B)) <= 255 and 0 <= int(integer(C)) <= 255 and 0 <= int(integer(D)) <= 255:
print('Yes')
else:
print('No')



为什么输入25555也会输出yes？😳😳