import java.math.BigInteger;
import java.util.*;

public class Main {
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    BigInteger x = new BigInteger(sc.next());
    BigInteger c = new BigInteger("100");
    BigInteger r = new BigInteger("100");
    long count = 0L;
    while(c.compareTo(x) < 0) {
      BigInteger tmp = c.divide(r);
      c = c.add(tmp);
      count++;
    }
    System.out.println(count);
  }
} import java.math.BigInteger; BigInteger java.math import java.util.*; util.* java public class Main {
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    BigInteger x = new BigInteger(sc.next());
    BigInteger c = new BigInteger("100");
    BigInteger r = new BigInteger("100");
    long count = 0L;
    while(c.compareTo(x) < 0) {
      BigInteger tmp = c.divide(r);
      c = c.add(tmp);
      count++;
    }
    System.out.println(count);
  }
} Main public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    BigInteger x = new BigInteger(sc.next());
    BigInteger c = new BigInteger("100");
    BigInteger r = new BigInteger("100");
    long count = 0L;
    while(c.compareTo(x) < 0) {
      BigInteger tmp = c.divide(r);
      c = c.add(tmp);
      count++;
    }
    System.out.println(count);
  } main {
    Scanner sc = new Scanner(System.in);
    BigInteger x = new BigInteger(sc.next());
    BigInteger c = new BigInteger("100");
    BigInteger r = new BigInteger("100");
    long count = 0L;
    while(c.compareTo(x) < 0) {
      BigInteger tmp = c.divide(r);
      c = c.add(tmp);
      count++;
    }
    System.out.println(count);
  } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) BigInteger x = new BigInteger(sc.next()); x new BigInteger(sc.next()) BigInteger c = new BigInteger("100"); c new BigInteger("100") BigInteger r = new BigInteger("100"); r new BigInteger("100") long count = 0L; count 0L while(c.compareTo(x) < 0) {
      BigInteger tmp = c.divide(r);
      c = c.add(tmp);
      count++;
    } c.compareTo(x) < 0 c.compareTo(x) c.compareTo c x 0 {
      BigInteger tmp = c.divide(r);
      c = c.add(tmp);
      count++;
    } BigInteger tmp = c.divide(r); tmp c.divide(r) c.divide c r c = c.add(tmp) c c.add(tmp) c.add c tmp count++ count System.out.println(count) System.out.println System.out System System.out count String[] args args public class Main {
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    BigInteger x = new BigInteger(sc.next());
    BigInteger c = new BigInteger("100");
    BigInteger r = new BigInteger("100");
    long count = 0L;
    while(c.compareTo(x) < 0) {
      BigInteger tmp = c.divide(r);
      c = c.add(tmp);
      count++;
    }
    System.out.println(count);
  }
} public class Main {
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    BigInteger x = new BigInteger(sc.next());
    BigInteger c = new BigInteger("100");
    BigInteger r = new BigInteger("100");
    long count = 0L;
    while(c.compareTo(x) < 0) {
      BigInteger tmp = c.divide(r);
      c = c.add(tmp);
      count++;
    }
    System.out.println(count);
  }
} Main
import java.math.BigInteger;
import java.util.*;

public class Main {
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    BigInteger x = new BigInteger(sc.next());
    BigInteger c = new BigInteger("100");
    BigInteger r = new BigInteger("100");
    long count = 0L;
    while(c.compareTo(x) < 0) {
      BigInteger tmp = c.divide(r);
      c = c.add(tmp);
      count++;
    }
    System.out.println(count);
  }
}
