import java.util.*;
 
public class Main{
  public static void main(String[]args){
    Scanner sc =  new Scanner(System.in);
    long N = Long.parseLong(sc.nextLine());
    
    int ans = 0;
    long m = 100;
    while(m < N){
      m += (long)(m*0.01);
      ans++;
    }
    System.out.println(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