import java.util.Scanner;
public class Main {

    public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
      
      //入力
      long X = sc.nextLong();//目標額
      long money = 100;
      long year =0; 
      
      //預金額が目標額以上になるまで
      while(money<X){
       money *= 1.01;
       year =year+1;
      }
      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