import java.util.*;
public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    long x = sc.nextLong();
    long now = 100l;
    long year = 0l;
    while(now < x){
      year++;
      now += now / 100;
    }
    System.out.println(year);
  }
} 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 now = 100l;
    long year = 0l;
    while(now < x){
      year++;
      now += now / 100;
    }
    System.out.println(year);
  }
} Main public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    long x = sc.nextLong();
    long now = 100l;
    long year = 0l;
    while(now < x){
      year++;
      now += now / 100;
    }
    System.out.println(year);
  } main {
    Scanner sc = new Scanner(System.in);
    long x = sc.nextLong();
    long now = 100l;
    long year = 0l;
    while(now < x){
      year++;
      now += now / 100;
    }
    System.out.println(year);
  } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) long x = sc.nextLong(); x sc.nextLong() sc.nextLong sc long now = 100l; now 100l long year = 0l; year 0l while(now < x){
      year++;
      now += now / 100;
    } now < x now x {
      year++;
      now += now / 100;
    } year++ year now += now / 100 now now / 100 now 100 System.out.println(year) System.out.println System.out System System.out year String[] args args public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    long x = sc.nextLong();
    long now = 100l;
    long year = 0l;
    while(now < x){
      year++;
      now += now / 100;
    }
    System.out.println(year);
  }
} public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    long x = sc.nextLong();
    long now = 100l;
    long year = 0l;
    while(now < x){
      year++;
      now += now / 100;
    }
    System.out.println(year);
  }
} Main
import java.util.*;
public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    long x = sc.nextLong();
    long now = 100l;
    long year = 0l;
    while(now < x){
      year++;
      now += now / 100;
    }
    System.out.println(year);
  }
}
