import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);

		long x = sc.nextLong();

		double m = 100;

		int i;

		for(i = 0; m < x; i++) {
			m = Math.floor(m * 1.01);
		}

		System.out.println(i);

		sc.close();

	}

} 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();

		double m = 100;

		int i;

		for(i = 0; m < x; i++) {
			m = Math.floor(m * 1.01);
		}

		System.out.println(i);

		sc.close();

	}

} Main public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);

		long x = sc.nextLong();

		double m = 100;

		int i;

		for(i = 0; m < x; i++) {
			m = Math.floor(m * 1.01);
		}

		System.out.println(i);

		sc.close();

	} main {

		Scanner sc = new Scanner(System.in);

		long x = sc.nextLong();

		double m = 100;

		int i;

		for(i = 0; m < x; i++) {
			m = Math.floor(m * 1.01);
		}

		System.out.println(i);

		sc.close();

	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) long x = sc.nextLong(); x sc.nextLong() sc.nextLong sc double m = 100; m 100 int i; i for(i = 0; m < x; i++) {
			m = Math.floor(m * 1.01);
		} i = 0; i = 0 i 0 m < x m x i++ i++ i {
			m = Math.floor(m * 1.01);
		} {
			m = Math.floor(m * 1.01);
		} m = Math.floor(m * 1.01) m Math.floor(m * 1.01) Math.floor Math m * 1.01 m 1.01 System.out.println(i) System.out.println System.out System System.out i sc.close() sc.close sc String[] args args public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);

		long x = sc.nextLong();

		double m = 100;

		int i;

		for(i = 0; m < x; i++) {
			m = Math.floor(m * 1.01);
		}

		System.out.println(i);

		sc.close();

	}

} public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);

		long x = sc.nextLong();

		double m = 100;

		int i;

		for(i = 0; m < x; i++) {
			m = Math.floor(m * 1.01);
		}

		System.out.println(i);

		sc.close();

	}

} Main
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);

		long x = sc.nextLong();

		double m = 100;

		int i;

		for(i = 0; m < x; i++) {
			m = Math.floor(m * 1.01);
		}

		System.out.println(i);

		sc.close();

	}

}
