import java.util.*;

class Main{
    static long digits(long n){
        long res = 0;
        while(n > 0){
            res++;
            n /= 10; 
        }
        return res;
    }
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        long N = sc.nextLong();

        long f = 0;
        long ans = Long.MAX_VALUE;
        for(long i = 1; i*i <= N; i++){
            if(N % i == 0){
            f = Math.max(digits(i), digits(N / i));
            ans = Math.min(ans, f);
            }
        }
        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