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 scan = new Scanner(System.in);
		long x = scan.nextLong();
		long p = 100;
		long ans = 0;
		
		while(true) {
			if(p < x) {
				p = p + (p/100);
				ans++;
			}
			else {
				break;
			}
		}
		
		System.out.println(ans);
		
	}

} 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 scan = new Scanner(System.in);
		long x = scan.nextLong();
		long p = 100;
		long ans = 0;
		
		while(true) {
			if(p < x) {
				p = p + (p/100);
				ans++;
			}
			else {
				break;
			}
		}
		
		System.out.println(ans);
		
	}

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

} 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 scan = new Scanner(System.in);
		long x = scan.nextLong();
		long p = 100;
		long ans = 0;
		
		while(true) {
			if(p < x) {
				p = p + (p/100);
				ans++;
			}
			else {
				break;
			}
		}
		
		System.out.println(ans);
		
	}

} 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 scan = new Scanner(System.in);
		long x = scan.nextLong();
		long p = 100;
		long ans = 0;
		
		while(true) {
			if(p < x) {
				p = p + (p/100);
				ans++;
			}
			else {
				break;
			}
		}
		
		System.out.println(ans);
		
	}

}
