import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner sc = new Scanner(System.in);
		long x = sc.nextLong();
		
		long temp = 100;
		int count = 0;
		while(true) {
			
			if(temp >= x) break;
			
			temp += temp / 100;
			count++;
		}
		
		System.out.println(count);
		
	}

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

	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner sc = new Scanner(System.in);
		long x = sc.nextLong();
		
		long temp = 100;
		int count = 0;
		while(true) {
			
			if(temp >= x) break;
			
			temp += temp / 100;
			count++;
		}
		
		System.out.println(count);
		
	}

} Main public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner sc = new Scanner(System.in);
		long x = sc.nextLong();
		
		long temp = 100;
		int count = 0;
		while(true) {
			
			if(temp >= x) break;
			
			temp += temp / 100;
			count++;
		}
		
		System.out.println(count);
		
	} main {
		// TODO 自動生成されたメソッド・スタブ
		Scanner sc = new Scanner(System.in);
		long x = sc.nextLong();
		
		long temp = 100;
		int count = 0;
		while(true) {
			
			if(temp >= x) break;
			
			temp += temp / 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 temp = 100; temp 100 int count = 0; count 0 while(true) {
			
			if(temp >= x) break;
			
			temp += temp / 100;
			count++;
		} true {
			
			if(temp >= x) break;
			
			temp += temp / 100;
			count++;
		} if(temp >= x) break; temp >= x temp x break; temp += temp / 100 temp temp / 100 temp 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) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner sc = new Scanner(System.in);
		long x = sc.nextLong();
		
		long temp = 100;
		int count = 0;
		while(true) {
			
			if(temp >= x) break;
			
			temp += temp / 100;
			count++;
		}
		
		System.out.println(count);
		
	}

} public class Main {

	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner sc = new Scanner(System.in);
		long x = sc.nextLong();
		
		long temp = 100;
		int count = 0;
		while(true) {
			
			if(temp >= x) break;
			
			temp += temp / 100;
			count++;
		}
		
		System.out.println(count);
		
	}

} Main
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner sc = new Scanner(System.in);
		long x = sc.nextLong();
		
		long temp = 100;
		int count = 0;
		while(true) {
			
			if(temp >= x) break;
			
			temp += temp / 100;
			count++;
		}
		
		System.out.println(count);
		
	}

}
