理解概念就容易了

while True:
    try:
        n=int(input())
        count=0
        for i in range(n+1):
            t=0
            t=i*i
            if str(t).endswith(str(i)):#用endwith就行了，转换成字符串就可以了
                count+=1
        print(count)
        
    except:
        break