import java.util.Scanner;


public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		long x = sc.nextLong();
		long ans = 0;
		long cash = 100;
		while(cash < x) {
			cash *= 1.01;
			ans++;
		}
		
		System.out.println(ans);
		sc.close();
	}

} 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 ans = 0;
		long cash = 100;
		while(cash < x) {
			cash *= 1.01;
			ans++;
		}
		
		System.out.println(ans);
		sc.close();
	}

} Main public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		long x = sc.nextLong();
		long ans = 0;
		long cash = 100;
		while(cash < x) {
			cash *= 1.01;
			ans++;
		}
		
		System.out.println(ans);
		sc.close();
	} main {

		Scanner sc = new Scanner(System.in);
		long x = sc.nextLong();
		long ans = 0;
		long cash = 100;
		while(cash < x) {
			cash *= 1.01;
			ans++;
		}
		
		System.out.println(ans);
		sc.close();
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) long x = sc.nextLong(); x sc.nextLong() sc.nextLong sc long ans = 0; ans 0 long cash = 100; cash 100 while(cash < x) {
			cash *= 1.01;
			ans++;
		} cash < x cash x {
			cash *= 1.01;
			ans++;
		} cash *= 1.01 cash 1.01 ans++ ans System.out.println(ans) System.out.println System.out System System.out ans sc.close() sc.close sc String[] args args public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		long x = sc.nextLong();
		long ans = 0;
		long cash = 100;
		while(cash < x) {
			cash *= 1.01;
			ans++;
		}
		
		System.out.println(ans);
		sc.close();
	}

} public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		long x = sc.nextLong();
		long ans = 0;
		long cash = 100;
		while(cash < x) {
			cash *= 1.01;
			ans++;
		}
		
		System.out.println(ans);
		sc.close();
	}

} 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 ans = 0;
		long cash = 100;
		while(cash < x) {
			cash *= 1.01;
			ans++;
		}
		
		System.out.println(ans);
		sc.close();
	}

}