import java.util.Scanner;

public class Main {
	public static void main(String[] args) throws Exception {
		Scanner sc = new Scanner(System.in);
		long X = sc.nextLong();
		long amount = 100;
		long res = 0;
		while(amount<X) {
			amount+=amount/100;
			res++;
		}
		System.out.println(res);
	}
} import java.util.Scanner; Scanner java.util public class Main {
	public static void main(String[] args) throws Exception {
		Scanner sc = new Scanner(System.in);
		long X = sc.nextLong();
		long amount = 100;
		long res = 0;
		while(amount<X) {
			amount+=amount/100;
			res++;
		}
		System.out.println(res);
	}
} Main public static void main(String[] args) throws Exception {
		Scanner sc = new Scanner(System.in);
		long X = sc.nextLong();
		long amount = 100;
		long res = 0;
		while(amount<X) {
			amount+=amount/100;
			res++;
		}
		System.out.println(res);
	} main {
		Scanner sc = new Scanner(System.in);
		long X = sc.nextLong();
		long amount = 100;
		long res = 0;
		while(amount<X) {
			amount+=amount/100;
			res++;
		}
		System.out.println(res);
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) long X = sc.nextLong(); X sc.nextLong() sc.nextLong sc long amount = 100; amount 100 long res = 0; res 0 while(amount<X) {
			amount+=amount/100;
			res++;
		} amount<X amount X {
			amount+=amount/100;
			res++;
		} amount+=amount/100 amount amount/100 amount 100 res++ res System.out.println(res) System.out.println System.out System System.out res String[] args args public class Main {
	public static void main(String[] args) throws Exception {
		Scanner sc = new Scanner(System.in);
		long X = sc.nextLong();
		long amount = 100;
		long res = 0;
		while(amount<X) {
			amount+=amount/100;
			res++;
		}
		System.out.println(res);
	}
} public class Main {
	public static void main(String[] args) throws Exception {
		Scanner sc = new Scanner(System.in);
		long X = sc.nextLong();
		long amount = 100;
		long res = 0;
		while(amount<X) {
			amount+=amount/100;
			res++;
		}
		System.out.println(res);
	}
} Main
import java.util.Scanner;

public class Main {
	public static void main(String[] args) throws Exception {
		Scanner sc = new Scanner(System.in);
		long X = sc.nextLong();
		long amount = 100;
		long res = 0;
		while(amount<X) {
			amount+=amount/100;
			res++;
		}
		System.out.println(res);
	}
}