import java.util.*;
 
public class Main{
  public static void main(String[]args){
    Scanner sc =  new Scanner(System.in);
    long N = Long.parseLong(sc.nextLine());
    
    int ans = 0;
    long m = 100;
    while(m < N){
      m += (long)(m*0.01);
      ans++;
    }
    System.out.println(ans);
  }
} import java.util.*; util.* java public class Main{
  public static void main(String[]args){
    Scanner sc =  new Scanner(System.in);
    long N = Long.parseLong(sc.nextLine());
    
    int ans = 0;
    long m = 100;
    while(m < N){
      m += (long)(m*0.01);
      ans++;
    }
    System.out.println(ans);
  }
} Main public static void main(String[]args){
    Scanner sc =  new Scanner(System.in);
    long N = Long.parseLong(sc.nextLine());
    
    int ans = 0;
    long m = 100;
    while(m < N){
      m += (long)(m*0.01);
      ans++;
    }
    System.out.println(ans);
  } main {
    Scanner sc =  new Scanner(System.in);
    long N = Long.parseLong(sc.nextLine());
    
    int ans = 0;
    long m = 100;
    while(m < N){
      m += (long)(m*0.01);
      ans++;
    }
    System.out.println(ans);
  } Scanner sc =  new Scanner(System.in); sc new Scanner(System.in) long N = Long.parseLong(sc.nextLine()); N Long.parseLong(sc.nextLine()) Long.parseLong Long sc.nextLine() sc.nextLine sc int ans = 0; ans 0 long m = 100; m 100 while(m < N){
      m += (long)(m*0.01);
      ans++;
    } m < N m N {
      m += (long)(m*0.01);
      ans++;
    } m += (long)(m*0.01) m (long)(m*0.01) m 0.01 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 sc =  new Scanner(System.in);
    long N = Long.parseLong(sc.nextLine());
    
    int ans = 0;
    long m = 100;
    while(m < N){
      m += (long)(m*0.01);
      ans++;
    }
    System.out.println(ans);
  }
} public class Main{
  public static void main(String[]args){
    Scanner sc =  new Scanner(System.in);
    long N = Long.parseLong(sc.nextLine());
    
    int ans = 0;
    long m = 100;
    while(m < N){
      m += (long)(m*0.01);
      ans++;
    }
    System.out.println(ans);
  }
} Main
import java.util.*;
 
public class Main{
  public static void main(String[]args){
    Scanner sc =  new Scanner(System.in);
    long N = Long.parseLong(sc.nextLine());
    
    int ans = 0;
    long m = 100;
    while(m < N){
      m += (long)(m*0.01);
      ans++;
    }
    System.out.println(ans);
  }
}