import java.util.*;
public class Main {

  public static void main(String[] args) { 
      Scanner sc = new Scanner(System.in);
      long x = sc.nextLong();

      long start = 100;
      long yrs = 0;
      while(start < x) {
        long unitInc = start / 100;
        start = start + unitInc;
        yrs++;

      }
      System.out.println(yrs);
  }
} import java.util.*; util.* java public class Main {

  public static void main(String[] args) { 
      Scanner sc = new Scanner(System.in);
      long x = sc.nextLong();

      long start = 100;
      long yrs = 0;
      while(start < x) {
        long unitInc = start / 100;
        start = start + unitInc;
        yrs++;

      }
      System.out.println(yrs);
  }
} Main public static void main(String[] args) { 
      Scanner sc = new Scanner(System.in);
      long x = sc.nextLong();

      long start = 100;
      long yrs = 0;
      while(start < x) {
        long unitInc = start / 100;
        start = start + unitInc;
        yrs++;

      }
      System.out.println(yrs);
  } main { 
      Scanner sc = new Scanner(System.in);
      long x = sc.nextLong();

      long start = 100;
      long yrs = 0;
      while(start < x) {
        long unitInc = start / 100;
        start = start + unitInc;
        yrs++;

      }
      System.out.println(yrs);
  } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) long x = sc.nextLong(); x sc.nextLong() sc.nextLong sc long start = 100; start 100 long yrs = 0; yrs 0 while(start < x) {
        long unitInc = start / 100;
        start = start + unitInc;
        yrs++;

      } start < x start x {
        long unitInc = start / 100;
        start = start + unitInc;
        yrs++;

      } long unitInc = start / 100; unitInc start / 100 start 100 start = start + unitInc start start + unitInc start unitInc yrs++ yrs System.out.println(yrs) System.out.println System.out System System.out yrs String[] args args public class Main {

  public static void main(String[] args) { 
      Scanner sc = new Scanner(System.in);
      long x = sc.nextLong();

      long start = 100;
      long yrs = 0;
      while(start < x) {
        long unitInc = start / 100;
        start = start + unitInc;
        yrs++;

      }
      System.out.println(yrs);
  }
} public class Main {

  public static void main(String[] args) { 
      Scanner sc = new Scanner(System.in);
      long x = sc.nextLong();

      long start = 100;
      long yrs = 0;
      while(start < x) {
        long unitInc = start / 100;
        start = start + unitInc;
        yrs++;

      }
      System.out.println(yrs);
  }
} Main
import java.util.*;
public class Main {

  public static void main(String[] args) { 
      Scanner sc = new Scanner(System.in);
      long x = sc.nextLong();

      long start = 100;
      long yrs = 0;
      while(start < x) {
        long unitInc = start / 100;
        start = start + unitInc;
        yrs++;

      }
      System.out.println(yrs);
  }
}