import java.util.Scanner;

public class Main {
	  
	public static void main(String args[]) {
		    Scanner sc = new Scanner(System.in);
		    
		    long N = sc.nextLong();
		    int waru = 0;
		    for(int i = 1; i <= Math.sqrt(N); i++) {
		    	if(N % i == 0) {
		    		waru = i;
		    	}
		    	else {
		    	}
		    }
		    long shou = N / waru;
		    int kotae = 0;
		    
		    while(shou != 0){
		    	shou = shou/10;
		    	kotae++;
		    }
		    System.out.println(kotae);
		    
		    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