import java.util.*;

public class Main {
  
  public static void main(String args[]){
    
    Scanner sc = new Scanner(System.in);
    
    long x = sc.nextLong();
    long year = 0;
    
    double kingaku = 100;
    
    do{
      
      kingaku = kingaku * 1.01;
      kingaku = Math.floor(kingaku);
      year++;
    }while(kingaku < x);
    
    System.out.println(year);
    
  }
  
}
/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