import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long X = sc.nextLong();
		long money = 100;
		int count = 0;
		while(true){
			money += money * 0.01;
			//System.out.println(money);
			count++;
			if(money >= X){
				System.out.println(count);
				return;
			}
		}
	}

} 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 money = 100;
		int count = 0;
		while(true){
			money += money * 0.01;
			//System.out.println(money);
			count++;
			if(money >= X){
				System.out.println(count);
				return;
			}
		}
	}

} Main public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long X = sc.nextLong();
		long money = 100;
		int count = 0;
		while(true){
			money += money * 0.01;
			//System.out.println(money);
			count++;
			if(money >= X){
				System.out.println(count);
				return;
			}
		}
	} main {
		Scanner sc = new Scanner(System.in);
		long X = sc.nextLong();
		long money = 100;
		int count = 0;
		while(true){
			money += money * 0.01;
			//System.out.println(money);
			count++;
			if(money >= X){
				System.out.println(count);
				return;
			}
		}
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) long X = sc.nextLong(); X sc.nextLong() sc.nextLong sc long money = 100; money 100 int count = 0; count 0 while(true){
			money += money * 0.01;
			//System.out.println(money);
			count++;
			if(money >= X){
				System.out.println(count);
				return;
			}
		} true {
			money += money * 0.01;
			//System.out.println(money);
			count++;
			if(money >= X){
				System.out.println(count);
				return;
			}
		} money += money * 0.01 money money * 0.01 money 0.01 count++ count if(money >= X){
				System.out.println(count);
				return;
			} money >= X money X {
				System.out.println(count);
				return;
			} System.out.println(count) System.out.println System.out System System.out count return; String[] args args public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long X = sc.nextLong();
		long money = 100;
		int count = 0;
		while(true){
			money += money * 0.01;
			//System.out.println(money);
			count++;
			if(money >= X){
				System.out.println(count);
				return;
			}
		}
	}

} public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long X = sc.nextLong();
		long money = 100;
		int count = 0;
		while(true){
			money += money * 0.01;
			//System.out.println(money);
			count++;
			if(money >= X){
				System.out.println(count);
				return;
			}
		}
	}

} 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 money = 100;
		int count = 0;
		while(true){
			money += money * 0.01;
			//System.out.println(money);
			count++;
			if(money >= X){
				System.out.println(count);
				return;
			}
		}
	}

}