import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long x = sc.nextLong();
		long now = 100;
		long ans = 0;

		while (now < x) {
			now +=  now / 100;
			ans++;
		}

		System.out.println(ans);

		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();
		long now = 100;
		long ans = 0;

		while (now < x) {
			now +=  now / 100;
			ans++;
		}

		System.out.println(ans);

		sc.close();
	}

} Main public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long x = sc.nextLong();
		long now = 100;
		long ans = 0;

		while (now < x) {
			now +=  now / 100;
			ans++;
		}

		System.out.println(ans);

		sc.close();
	} main {
		Scanner sc = new Scanner(System.in);
		long x = sc.nextLong();
		long now = 100;
		long ans = 0;

		while (now < x) {
			now +=  now / 100;
			ans++;
		}

		System.out.println(ans);

		sc.close();
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) long x = sc.nextLong(); x sc.nextLong() sc.nextLong sc long now = 100; now 100 long ans = 0; ans 0 while (now < x) {
			now +=  now / 100;
			ans++;
		} now < x now x {
			now +=  now / 100;
			ans++;
		} now +=  now / 100 now now / 100 now 100 ans++ ans System.out.println(ans) System.out.println System.out System System.out ans 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();
		long now = 100;
		long ans = 0;

		while (now < x) {
			now +=  now / 100;
			ans++;
		}

		System.out.println(ans);

		sc.close();
	}

} public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long x = sc.nextLong();
		long now = 100;
		long ans = 0;

		while (now < x) {
			now +=  now / 100;
			ans++;
		}

		System.out.println(ans);

		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();
		long now = 100;
		long ans = 0;

		while (now < x) {
			now +=  now / 100;
			ans++;
		}

		System.out.println(ans);

		sc.close();
	}

}
