import java.util.*;
public class Main {

  public static void main(String[] args) { 
      Scanner sc = new Scanner(System.in);
      long n = sc.nextLong();
      int minLen = Integer.MAX_VALUE;
      for(long i = 1; i * i <= n; i++) {
        if(n % i == 0)
          minLen = Math.min(minLen, calDigit(Math.max(i, n / i)));
      }
      System.out.println(minLen);
  }

  private static int calDigit(long n) {
    int cnt = 0;
    while(n > 0) {
      cnt++;
      n /= 10;
    }
    return cnt;
  }
}
/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