import java.util.*;
public class Main{
	public static void main(String args[]){
		Scanner sc = new Scanner(System.in);
		long N = sc.nextLong();
		int ans = keta(N);
		for(long i = 1;i <= N / i;i++){
			if(N % i == 0){
				ans = Math.min(ans,keta(Math.max(N / i,i)));
			}
		}
		System.out.println(ans);
	}
	public static int keta(long a){
		int count = 1;
		long buf = a;
		while(buf / 10 != 0){
			count++;
			buf = buf / 10;
		}
		return count;
	}
}
/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