import java.io.*;
import java.util.*;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		PrintWriter out = new PrintWriter(System.out);
		// ------------------------------------------------
		long x = Long.parseLong(sc.next());

		int ret = 0;
		long kane = 100;
		while (kane < x) {
			kane += kane / 100;
			ret++;
		}

		out.println(ret);

		// ------------------------------------------------
		sc.close();
		out.flush();
	}
} import java.io.*; io.* java import java.util.*; util.* java public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		PrintWriter out = new PrintWriter(System.out);
		// ------------------------------------------------
		long x = Long.parseLong(sc.next());

		int ret = 0;
		long kane = 100;
		while (kane < x) {
			kane += kane / 100;
			ret++;
		}

		out.println(ret);

		// ------------------------------------------------
		sc.close();
		out.flush();
	}
} Main public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		PrintWriter out = new PrintWriter(System.out);
		// ------------------------------------------------
		long x = Long.parseLong(sc.next());

		int ret = 0;
		long kane = 100;
		while (kane < x) {
			kane += kane / 100;
			ret++;
		}

		out.println(ret);

		// ------------------------------------------------
		sc.close();
		out.flush();
	} main {
		Scanner sc = new Scanner(System.in);
		PrintWriter out = new PrintWriter(System.out);
		// ------------------------------------------------
		long x = Long.parseLong(sc.next());

		int ret = 0;
		long kane = 100;
		while (kane < x) {
			kane += kane / 100;
			ret++;
		}

		out.println(ret);

		// ------------------------------------------------
		sc.close();
		out.flush();
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) PrintWriter out = new PrintWriter(System.out); out new PrintWriter(System.out) long x = Long.parseLong(sc.next()); x Long.parseLong(sc.next()) Long.parseLong Long sc.next() sc.next sc int ret = 0; ret 0 long kane = 100; kane 100 while (kane < x) {
			kane += kane / 100;
			ret++;
		} kane < x kane x {
			kane += kane / 100;
			ret++;
		} kane += kane / 100 kane kane / 100 kane 100 ret++ ret out.println(ret) out.println out ret sc.close() sc.close sc out.flush() out.flush out String[] args args public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		PrintWriter out = new PrintWriter(System.out);
		// ------------------------------------------------
		long x = Long.parseLong(sc.next());

		int ret = 0;
		long kane = 100;
		while (kane < x) {
			kane += kane / 100;
			ret++;
		}

		out.println(ret);

		// ------------------------------------------------
		sc.close();
		out.flush();
	}
} public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		PrintWriter out = new PrintWriter(System.out);
		// ------------------------------------------------
		long x = Long.parseLong(sc.next());

		int ret = 0;
		long kane = 100;
		while (kane < x) {
			kane += kane / 100;
			ret++;
		}

		out.println(ret);

		// ------------------------------------------------
		sc.close();
		out.flush();
	}
} Main
import java.io.*;
import java.util.*;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		PrintWriter out = new PrintWriter(System.out);
		// ------------------------------------------------
		long x = Long.parseLong(sc.next());

		int ret = 0;
		long kane = 100;
		while (kane < x) {
			kane += kane / 100;
			ret++;
		}

		out.println(ret);

		// ------------------------------------------------
		sc.close();
		out.flush();
	}
}