import java.util.Scanner;

public class Main {

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

		while(true) {
			money = money + money / 100;
			cnt++;
			if(money >= x) break;
		}
		System.out.println(cnt);

	}

} import java.util.Scanner; Scanner java.util public class Main {

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

		while(true) {
			money = money + money / 100;
			cnt++;
			if(money >= x) break;
		}
		System.out.println(cnt);

	}

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

		while(true) {
			money = money + money / 100;
			cnt++;
			if(money >= x) break;
		}
		System.out.println(cnt);

	} main {
		Scanner sc = new Scanner(System.in);
		long money = 100;
		long x = sc.nextLong();
		int cnt = 0;

		while(true) {
			money = money + money / 100;
			cnt++;
			if(money >= x) break;
		}
		System.out.println(cnt);

	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) long money = 100; money 100 long x = sc.nextLong(); x sc.nextLong() sc.nextLong sc int cnt = 0; cnt 0 while(true) {
			money = money + money / 100;
			cnt++;
			if(money >= x) break;
		} true {
			money = money + money / 100;
			cnt++;
			if(money >= x) break;
		} money = money + money / 100 money money + money / 100 money money / 100 money 100 cnt++ cnt if(money >= x) break; money >= x money x break; System.out.println(cnt) System.out.println System.out System System.out cnt String[] args args public class Main {

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

		while(true) {
			money = money + money / 100;
			cnt++;
			if(money >= x) break;
		}
		System.out.println(cnt);

	}

} public class Main {

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

		while(true) {
			money = money + money / 100;
			cnt++;
			if(money >= x) break;
		}
		System.out.println(cnt);

	}

} Main
import java.util.Scanner;

public class Main {

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

		while(true) {
			money = money + money / 100;
			cnt++;
			if(money >= x) break;
		}
		System.out.println(cnt);

	}

}