import java.util.Scanner;
 
public class Main {
 
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    final long x = sc.nextLong();
    long l = 100;
    for(int i=0;;i++){
      if(l >= x){
        System.out.println(i);
        break;
      }
      l += l / 100;
    }
  }
}
/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