import java.util.*;

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

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