import java.util.*;
public class Main {
	
	public static void main(String... args) {
		Scanner sc = new Scanner(System.in);
		
		long N = sc.nextLong();
		
		long sqrt = (long)Math.sqrt(N);
		for (long i = sqrt; i >= 1; i--) {
			if (N % i == 0) {
				int ans = Math.max(String.valueOf(i).length(), String.valueOf(N / i).length());
				System.out.println(ans);
				return;
			}
		}
	}
}
/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