import java.util.Scanner;

public class Main {
	static final int a = 100;
	static final double r = 1.01;

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long x = Long.parseLong(sc.next());
		System.out.println(solve(x));
	}

	static public int solve(long x) {
		int year = 0;
		for (long i = a;; i = (long) (i * r), year++) {
			if (i >= x)
				return year;
		}
	}

} import java.util.Scanner; Scanner java.util public class Main {
	static final int a = 100;
	static final double r = 1.01;

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long x = Long.parseLong(sc.next());
		System.out.println(solve(x));
	}

	static public int solve(long x) {
		int year = 0;
		for (long i = a;; i = (long) (i * r), year++) {
			if (i >= x)
				return year;
		}
	}

} Main static final int a = 100; a 100 static final double r = 1.01; r 1.01 public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long x = Long.parseLong(sc.next());
		System.out.println(solve(x));
	} main {
		Scanner sc = new Scanner(System.in);
		long x = Long.parseLong(sc.next());
		System.out.println(solve(x));
	} 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 System.out.println(solve(x)) System.out.println System.out System System.out solve(x) solve x String[] args args static public int solve(long x) {
		int year = 0;
		for (long i = a;; i = (long) (i * r), year++) {
			if (i >= x)
				return year;
		}
	} solve {
		int year = 0;
		for (long i = a;; i = (long) (i * r), year++) {
			if (i >= x)
				return year;
		}
	} int year = 0; year 0 for (long i = a;; i = (long) (i * r), year++) {
			if (i >= x)
				return year;
		} long i = a; long i = a; i a i = (long) (i * r), year++ i = (long) (i * r) i (long) (i * r) i r year++ year {
			if (i >= x)
				return year;
		} {
			if (i >= x)
				return year;
		} if (i >= x)
				return year; i >= x i x return year; year long x x public class Main {
	static final int a = 100;
	static final double r = 1.01;

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long x = Long.parseLong(sc.next());
		System.out.println(solve(x));
	}

	static public int solve(long x) {
		int year = 0;
		for (long i = a;; i = (long) (i * r), year++) {
			if (i >= x)
				return year;
		}
	}

} public class Main {
	static final int a = 100;
	static final double r = 1.01;

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long x = Long.parseLong(sc.next());
		System.out.println(solve(x));
	}

	static public int solve(long x) {
		int year = 0;
		for (long i = a;; i = (long) (i * r), year++) {
			if (i >= x)
				return year;
		}
	}

} Main
import java.util.Scanner;

public class Main {
	static final int a = 100;
	static final double r = 1.01;

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long x = Long.parseLong(sc.next());
		System.out.println(solve(x));
	}

	static public int solve(long x) {
		int year = 0;
		for (long i = a;; i = (long) (i * r), year++) {
			if (i >= x)
				return year;
		}
	}

}
