import java.util.Scanner;

public class Main {


	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long N = sc.nextLong();
		sc.close();

		int p = (int)Math.pow(N, 0.5);

		int ans = Integer.MAX_VALUE;
		for(int i = 1 ; i <= p ; i++){
			if(N%i == 0){
				ans = Math.min(ans, comp(i,N/i));
			}
		}

		System.out.println(ans);

	}
	private static int comp(long m, long n) {
	    if(Long.toString(m).length() >= Long.toString(n).length()){
	    	return Long.toString(m).length();
	    }
	    else{
	    	return Long.toString(n).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