题解 | #自守数#
自守数
https://www.nowcoder.com/practice/88ddd31618f04514ae3a689e83f3ab8e
n=int(input())
cnt=0
for i in range(n+1):
square=list(str(i**2))
l=len(str(i))
tail=int(''.join(square[-l:]))
#print(square,tail)
if tail==i:
cnt += 1
print(cnt)
