import java.util.*;
import java.io.PrintWriter;
import static java.lang.Integer.*;
import static java.lang.Long.*;
import static java.lang.Math.*;
import static java.lang.System.*;

public class Main {
	public static final int AB = 26;
	public static void main(String[] args) {
		long i=0,j=0,k=0;
		Scanner sc = new Scanner(in);
		long n = parseLong(sc.next());
		sc.close();
		long mn = 10;
		for (i = 1; i*i <= n; i++) {
			if(n%i==0) {
				long tmp=(long) Math.max(floor(log10(i)+1),floor(log10(n/i)+1));
				if(tmp<mn)mn=tmp;
			}
		}
		out.println(mn);
	}
}

/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