import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);

		long X = Long.parseLong(sc.next());

		long yokin = 100;
		int counter = 0;
		while (!(yokin >= X)) {
			yokin *= 1.01;
			counter++;
		}

		System.out.println(counter);
	}
} import java.util.Scanner; Scanner java.util public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);

		long X = Long.parseLong(sc.next());

		long yokin = 100;
		int counter = 0;
		while (!(yokin >= X)) {
			yokin *= 1.01;
			counter++;
		}

		System.out.println(counter);
	}
} Main public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);

		long X = Long.parseLong(sc.next());

		long yokin = 100;
		int counter = 0;
		while (!(yokin >= X)) {
			yokin *= 1.01;
			counter++;
		}

		System.out.println(counter);
	} main {
		Scanner sc = new Scanner(System.in);

		long X = Long.parseLong(sc.next());

		long yokin = 100;
		int counter = 0;
		while (!(yokin >= X)) {
			yokin *= 1.01;
			counter++;
		}

		System.out.println(counter);
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) long X = Long.parseLong(sc.next()); X Long.parseLong(sc.next()) Long.parseLong Long sc.next() sc.next sc long yokin = 100; yokin 100 int counter = 0; counter 0 while (!(yokin >= X)) {
			yokin *= 1.01;
			counter++;
		} !(yokin >= X) (yokin >= X) yokin X {
			yokin *= 1.01;
			counter++;
		} yokin *= 1.01 yokin 1.01 counter++ counter System.out.println(counter) System.out.println System.out System System.out counter String[] args args public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);

		long X = Long.parseLong(sc.next());

		long yokin = 100;
		int counter = 0;
		while (!(yokin >= X)) {
			yokin *= 1.01;
			counter++;
		}

		System.out.println(counter);
	}
} public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);

		long X = Long.parseLong(sc.next());

		long yokin = 100;
		int counter = 0;
		while (!(yokin >= X)) {
			yokin *= 1.01;
			counter++;
		}

		System.out.println(counter);
	}
} Main
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);

		long X = Long.parseLong(sc.next());

		long yokin = 100;
		int counter = 0;
		while (!(yokin >= X)) {
			yokin *= 1.01;
			counter++;
		}

		System.out.println(counter);
	}
}