import java.util.*;

public class Main{
  public static void main(String[] args){
    Scanner scan = new Scanner(System.in);
    long x = scan.nextLong();
    long z = 100;
    int sum = 0;
    while (z<x){
      long g = (long) z/100;
      z+=g;
      sum += 1;
    }
    System.out.println(sum);
  }
} import java.util.*; util.* java public class Main{
  public static void main(String[] args){
    Scanner scan = new Scanner(System.in);
    long x = scan.nextLong();
    long z = 100;
    int sum = 0;
    while (z<x){
      long g = (long) z/100;
      z+=g;
      sum += 1;
    }
    System.out.println(sum);
  }
} Main public static void main(String[] args){
    Scanner scan = new Scanner(System.in);
    long x = scan.nextLong();
    long z = 100;
    int sum = 0;
    while (z<x){
      long g = (long) z/100;
      z+=g;
      sum += 1;
    }
    System.out.println(sum);
  } main {
    Scanner scan = new Scanner(System.in);
    long x = scan.nextLong();
    long z = 100;
    int sum = 0;
    while (z<x){
      long g = (long) z/100;
      z+=g;
      sum += 1;
    }
    System.out.println(sum);
  } Scanner scan = new Scanner(System.in); scan new Scanner(System.in) long x = scan.nextLong(); x scan.nextLong() scan.nextLong scan long z = 100; z 100 int sum = 0; sum 0 while (z<x){
      long g = (long) z/100;
      z+=g;
      sum += 1;
    } z<x z x {
      long g = (long) z/100;
      z+=g;
      sum += 1;
    } long g = (long) z/100; g (long) z/100 (long) z 100 z+=g z g sum += 1 sum 1 System.out.println(sum) System.out.println System.out System System.out sum String[] args args public class Main{
  public static void main(String[] args){
    Scanner scan = new Scanner(System.in);
    long x = scan.nextLong();
    long z = 100;
    int sum = 0;
    while (z<x){
      long g = (long) z/100;
      z+=g;
      sum += 1;
    }
    System.out.println(sum);
  }
} public class Main{
  public static void main(String[] args){
    Scanner scan = new Scanner(System.in);
    long x = scan.nextLong();
    long z = 100;
    int sum = 0;
    while (z<x){
      long g = (long) z/100;
      z+=g;
      sum += 1;
    }
    System.out.println(sum);
  }
} Main
import java.util.*;

public class Main{
  public static void main(String[] args){
    Scanner scan = new Scanner(System.in);
    long x = scan.nextLong();
    long z = 100;
    int sum = 0;
    while (z<x){
      long g = (long) z/100;
      z+=g;
      sum += 1;
    }
    System.out.println(sum);
  }
}
