import java.util.Scanner;
public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    long X = sc.nextLong();
    long a = 100;
    long b = 0;
    //long b = 1;
    //long max = (int)Math.pow(10,18);
    long cnt = 0;

    for(int i=0; i<X; i++) {
      a+=a/100;
      b=a;
      cnt++;
      if(b>=X){
        break;
      }
      if(X<100){
        continue;
      }
    }
    System.out.println(cnt);
  }
}
/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