import java.util.*;

public class Main{
  public static void main(String[]args){
    Scanner sc = new Scanner(System.in);
    long N = sc.nextLong();
    long min = 100;
    for(long i = 1; i <= Math.sqrt(N); i++){
      if(N%i == 0){
        long A = calc(i, N/i);
        min = A < min ? A : min;
      }
    }
    System.out.println(min);
  }
  public static long calc(long A, long B){
    if(A < B){
      return calc(B, A);
    }
    int ans = 1;
    while(A/10 != 0){
      A /= 10;
      ans++;
    }
    return 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