import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		long n = scanner.nextLong();
		long min = Integer.MAX_VALUE;
		for(long i=1;i<=Math.sqrt(n);i++){
			if(n % i == 0){
				long x = n / i;
				String y = String.valueOf(i);
				String z = String.valueOf(x);
				long max = Math.max(y.length(), z.length());
				min = Math.min(min, max);
			}
		}
		System.out.println(min);
	}

}

/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