import java.util.Scanner;
class Main{
	   public static void main(String[] args){
	  Scanner scan =  new Scanner(System.in);
	   long a = scan.nextLong();
	   long e =0;
	   long f = a;
	   for(long i=1;i*i<=a;i++){ 
		   long b=0;
		   if(a%i==0){
			   b = a/i;
			   int d = String.valueOf( b ).length();
	           int c = String.valueOf(i).length();
	           e =  Math.max(d,c);
		   }
		   if(e<f){
			   f=e;
		   }
		   
	   }
	   System.out.println(f);
	   }
	}
/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