
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		
		Scanner cin = new Scanner(System.in);
		long X = cin.nextLong();
		long deposit = 100,count = 0;
		
		while(deposit<X) {
			deposit += deposit/100;
			count++;
		}
		
		System.out.println(count);
		return;
		
		
	}

} import java.util.Scanner; Scanner java.util public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		
		Scanner cin = new Scanner(System.in);
		long X = cin.nextLong();
		long deposit = 100,count = 0;
		
		while(deposit<X) {
			deposit += deposit/100;
			count++;
		}
		
		System.out.println(count);
		return;
		
		
	}

} Main public static void main(String[] args) {
		// TODO Auto-generated method stub
		
		Scanner cin = new Scanner(System.in);
		long X = cin.nextLong();
		long deposit = 100,count = 0;
		
		while(deposit<X) {
			deposit += deposit/100;
			count++;
		}
		
		System.out.println(count);
		return;
		
		
	} main {
		// TODO Auto-generated method stub
		
		Scanner cin = new Scanner(System.in);
		long X = cin.nextLong();
		long deposit = 100,count = 0;
		
		while(deposit<X) {
			deposit += deposit/100;
			count++;
		}
		
		System.out.println(count);
		return;
		
		
	} Scanner cin = new Scanner(System.in); cin new Scanner(System.in) long X = cin.nextLong(); X cin.nextLong() cin.nextLong cin long deposit = 100 deposit 100 count = 0; count 0 while(deposit<X) {
			deposit += deposit/100;
			count++;
		} deposit<X deposit X {
			deposit += deposit/100;
			count++;
		} deposit += deposit/100 deposit deposit/100 deposit 100 count++ count System.out.println(count) System.out.println System.out System System.out count return; String[] args args public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		
		Scanner cin = new Scanner(System.in);
		long X = cin.nextLong();
		long deposit = 100,count = 0;
		
		while(deposit<X) {
			deposit += deposit/100;
			count++;
		}
		
		System.out.println(count);
		return;
		
		
	}

} public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		
		Scanner cin = new Scanner(System.in);
		long X = cin.nextLong();
		long deposit = 100,count = 0;
		
		while(deposit<X) {
			deposit += deposit/100;
			count++;
		}
		
		System.out.println(count);
		return;
		
		
	}

} Main

import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		
		Scanner cin = new Scanner(System.in);
		long X = cin.nextLong();
		long deposit = 100,count = 0;
		
		while(deposit<X) {
			deposit += deposit/100;
			count++;
		}
		
		System.out.println(count);
		return;
		
		
	}

}