import java.util.Scanner;

class Main{

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long n=sc.nextLong();
		long sq=(long)(Math.sqrt(n)+0.0001);
		while(true){
			if(n%sq==0){
				break;
			}
			sq--;
		}
		System.out.println((int)Math.log10(n/sq)+1);
	}

}
/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