import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);

		long x = sc.nextLong(), m = 100L;
		int y = 0;

		while(m < x) {
			m += m / 100;
			y++;
		}

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

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);

		long x = sc.nextLong(), m = 100L;
		int y = 0;

		while(m < x) {
			m += m / 100;
			y++;
		}

		System.out.println(y);
	}
} Main public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);

		long x = sc.nextLong(), m = 100L;
		int y = 0;

		while(m < x) {
			m += m / 100;
			y++;
		}

		System.out.println(y);
	} main {

		Scanner sc = new Scanner(System.in);

		long x = sc.nextLong(), m = 100L;
		int y = 0;

		while(m < x) {
			m += m / 100;
			y++;
		}

		System.out.println(y);
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) long x = sc.nextLong() x sc.nextLong() sc.nextLong sc m = 100L; m 100L int y = 0; y 0 while(m < x) {
			m += m / 100;
			y++;
		} m < x m x {
			m += m / 100;
			y++;
		} m += m / 100 m m / 100 m 100 y++ y System.out.println(y) System.out.println System.out System System.out y String[] args args public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);

		long x = sc.nextLong(), m = 100L;
		int y = 0;

		while(m < x) {
			m += m / 100;
			y++;
		}

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

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);

		long x = sc.nextLong(), m = 100L;
		int y = 0;

		while(m < x) {
			m += m / 100;
			y++;
		}

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

public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);

		long x = sc.nextLong(), m = 100L;
		int y = 0;

		while(m < x) {
			m += m / 100;
			y++;
		}

		System.out.println(y);
	}
}