import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        double N = scanner.nextDouble();
        int ceil = (int)Math.ceil(Math.sqrt(N));
        int min = Integer.MAX_VALUE;
        for (int i = 1; i < Math.max(2, ceil+1); i++) {
            if(N%i == 0){
                int f = Math.max(String.valueOf(i).length(), String.format("%.0f", N/i).length());
                min = Math.min(f, min);
            }
        }

        System.out.println(min);
    }
}

/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