# 
# Solution to Project Euler problem 63
# Copyright (c) Project Nayuki. All rights reserved.
# 
# https://www.nayuki.io/page/project-euler-solutions
# https://github.com/nayuki/Project-Euler-solutions
# 


# Let's examine n^k for different values of n and k and see which
# choices cannot possibly work (i.e. not being exactly k digits long).
# 
# When n = 10, for each k, n^k has exactly k+1 digits, so these are excluded.
# By extension, when n > 10, for each k, n^k has at least k+1 digits, so these are excluded.
# Thus we should only consider 1 <= n <= 9.
# 
# When n = 9, k = 22, then n^k has 21 digits which is insufficient.
# Extending this, when n = 9 and k > 22, n^k has fewer than k digits.
# Furthermore, when n < 9, n^k will have start to have
# fewer than k digits at some value of k with k < 22.
# Therefore we should only consider 1 <= k <= 21.
# 
# We handle the rest of the testing by brute force.
def compute():
	ans = sum(1
		for i in range(1, 10)
		for j in range(1, 22)
		if len(str(i**j)) == j)
	return str(ans)


if __name__ == "__main__":
	print(compute())