import java.util.*;
public class Main
{
  public static void main(String[] args)
  {
    Scanner sc=new Scanner(System.in);
    long a=sc.nextLong();
    int t=0;
    long p=100;
    while(a>p)
    {
      p=p+p/100;
      t++;
    }
      System.out.println(t);
     
  }
}
/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