import java.util.*;
public class Main{
  public static void main(String[] args){
    Scanner scanner = new Scanner(System.in);
    double targetPrice = scanner.nextDouble();
    
    int year = 0;
    double result = 100.0;
    
    while(result < targetPrice){
      result = result + Math.floor(result * 0.01);
      year++;
    }
    
    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