import java.util.Scanner;

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

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