import java.util.*;

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

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