import  java.util.Scanner;
 
class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		long N = sc.nextLong();
		int ans = Integer.MAX_VALUE;
		for(long i = 1; i * i <= N; i++) {
			if(N % i == 0) {
				ans = Math.min(ans, Math.max(Long.toString(i).length(), Long.toString(N / i).length()));
			}
		}
		System.out.println(ans);
	}
}
/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