import java.util.Scanner;

public class Main {
  public static void main(String[] args) {
    Scanner scanner = new Scanner(System.in);

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

    long X = scanner.nextLong();
    long a = 100;
    int t = 0;
    while (a < X) {
      a += a / 100;
      t++;
    }
    System.out.println(t);
  }
} Main public static void main(String[] args) {
    Scanner scanner = new Scanner(System.in);

    long X = scanner.nextLong();
    long a = 100;
    int t = 0;
    while (a < X) {
      a += a / 100;
      t++;
    }
    System.out.println(t);
  } main {
    Scanner scanner = new Scanner(System.in);

    long X = scanner.nextLong();
    long a = 100;
    int t = 0;
    while (a < X) {
      a += a / 100;
      t++;
    }
    System.out.println(t);
  } Scanner scanner = new Scanner(System.in); scanner new Scanner(System.in) long X = scanner.nextLong(); X scanner.nextLong() scanner.nextLong scanner long a = 100; a 100 int t = 0; t 0 while (a < X) {
      a += a / 100;
      t++;
    } a < X a X {
      a += a / 100;
      t++;
    } a += a / 100 a a / 100 a 100 t++ t System.out.println(t) System.out.println System.out System System.out t String[] args args public class Main {
  public static void main(String[] args) {
    Scanner scanner = new Scanner(System.in);

    long X = scanner.nextLong();
    long a = 100;
    int t = 0;
    while (a < X) {
      a += a / 100;
      t++;
    }
    System.out.println(t);
  }
} public class Main {
  public static void main(String[] args) {
    Scanner scanner = new Scanner(System.in);

    long X = scanner.nextLong();
    long a = 100;
    int t = 0;
    while (a < X) {
      a += a / 100;
      t++;
    }
    System.out.println(t);
  }
} Main
import java.util.Scanner;

public class Main {
  public static void main(String[] args) {
    Scanner scanner = new Scanner(System.in);

    long X = scanner.nextLong();
    long a = 100;
    int t = 0;
    while (a < X) {
      a += a / 100;
      t++;
    }
    System.out.println(t);
  }
}
