
import java.util.Scanner;

public class Main {

	public static void main(String[] args) throws Exception {
		Scanner sc = new Scanner(System.in);
		long N = sc.nextLong();
		int ans = String.valueOf(N).length();
		for (long A = 1; A * A <= N; A++) {
			if (N % A != 0) {
				continue;
			}
			long B = N / A;
			int tmp = Math.max(String.valueOf(A).length(), String.valueOf(B).length());
			if (ans > tmp) {
				ans = tmp;
			}
		}
		System.out.println(ans);
		sc.close();
	}
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz