import sys for line in sys.stdin.readlines(): n = int(line) + 1 ret = 0 for i in range(0, n): if str(i * i).endswith(str(i)): ret += 1 print(ret)
import sys for line in sys.stdin.readlines(): n = int(line) + 1 ret = 0 for i in range(0, n): if str(i * i).endswith(str(i)): ret += 1 print(ret)