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