import java.util.*;

class Main{
public static void main(String[] args){
	Scanner sc = new Scanner(System.in);
	long n = sc.nextLong();
	for(int i=(int)Math.sqrt(n); i>=1; i--) {
		if(n%i == 0) {
			System.out.println(String.valueOf(n/i).length());
			break;
		}
	}
}
}
/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