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