public class Main {
    private static java.util.Scanner scanner = new java.util.Scanner(System.in);

    public static void main(String[] args) {
	    long n = scanner.nextLong(), ans = String.valueOf(n).length();
	    for (long i = 1; i * i <= n; i++)
            if (n % i == 0)
                ans = Math.min(ans, Math.max(String.valueOf(i).length(), String.valueOf(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