import java.util.*;
import java.lang.*;
public class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);

		long N = sc.nextLong();
		long ans = 0;
		for( long i=1; i*i<=N; i++ ){
			if( N%i==0 ){
				ans = N/i;
			}
		}
		String ss = String.valueOf(ans);
		System.out.println(ss.length());
	}
}

/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