import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		Long N = Long.parseLong(sc.next());
		sc.close();
		Long n = 0L;
		for(int i = (int)Math.sqrt(N);i > 0;i--) {
			if(N%i==0) {
				n = N/ i;
				break;
			}
		}
		System.out.println(n.toString().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