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());
		sc.close();

		long sum = 100;
		int count = 0;
		do {
			sum = (long) (sum * 1.01);
			count++;

		} while (sum < X);

		System.out.println(count);

	}

} 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());
		sc.close();

		long sum = 100;
		int count = 0;
		do {
			sum = (long) (sum * 1.01);
			count++;

		} while (sum < X);

		System.out.println(count);

	}

} Main public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long X = Long.parseLong(sc.next());
		sc.close();

		long sum = 100;
		int count = 0;
		do {
			sum = (long) (sum * 1.01);
			count++;

		} while (sum < X);

		System.out.println(count);

	} main {
		Scanner sc = new Scanner(System.in);
		long X = Long.parseLong(sc.next());
		sc.close();

		long sum = 100;
		int count = 0;
		do {
			sum = (long) (sum * 1.01);
			count++;

		} while (sum < X);

		System.out.println(count);

	} 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 sc.close() sc.close sc long sum = 100; sum 100 int count = 0; count 0 do {
			sum = (long) (sum * 1.01);
			count++;

		} while (sum < X); sum < X sum X {
			sum = (long) (sum * 1.01);
			count++;

		} sum = (long) (sum * 1.01) sum (long) (sum * 1.01) sum 1.01 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 = Long.parseLong(sc.next());
		sc.close();

		long sum = 100;
		int count = 0;
		do {
			sum = (long) (sum * 1.01);
			count++;

		} while (sum < X);

		System.out.println(count);

	}

} public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long X = Long.parseLong(sc.next());
		sc.close();

		long sum = 100;
		int count = 0;
		do {
			sum = (long) (sum * 1.01);
			count++;

		} while (sum < X);

		System.out.println(count);

	}

} 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());
		sc.close();

		long sum = 100;
		int count = 0;
		do {
			sum = (long) (sum * 1.01);
			count++;

		} while (sum < X);

		System.out.println(count);

	}

}
