import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		
		long x = scan.nextLong();
		scan.close();
		
		long ans = 0;
		long yen = 100;
		while(x > yen) {
			yen += yen/100;
			ans++;
		}
		
		System.out.println(ans);
	}
} import java.util.Scanner; Scanner java.util public class Main {
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		
		long x = scan.nextLong();
		scan.close();
		
		long ans = 0;
		long yen = 100;
		while(x > yen) {
			yen += yen/100;
			ans++;
		}
		
		System.out.println(ans);
	}
} Main public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		
		long x = scan.nextLong();
		scan.close();
		
		long ans = 0;
		long yen = 100;
		while(x > yen) {
			yen += yen/100;
			ans++;
		}
		
		System.out.println(ans);
	} main {
		Scanner scan = new Scanner(System.in);
		
		long x = scan.nextLong();
		scan.close();
		
		long ans = 0;
		long yen = 100;
		while(x > yen) {
			yen += yen/100;
			ans++;
		}
		
		System.out.println(ans);
	} Scanner scan = new Scanner(System.in); scan new Scanner(System.in) long x = scan.nextLong(); x scan.nextLong() scan.nextLong scan scan.close() scan.close scan long ans = 0; ans 0 long yen = 100; yen 100 while(x > yen) {
			yen += yen/100;
			ans++;
		} x > yen x yen {
			yen += yen/100;
			ans++;
		} yen += yen/100 yen yen/100 yen 100 ans++ ans System.out.println(ans) System.out.println System.out System System.out ans String[] args args public class Main {
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		
		long x = scan.nextLong();
		scan.close();
		
		long ans = 0;
		long yen = 100;
		while(x > yen) {
			yen += yen/100;
			ans++;
		}
		
		System.out.println(ans);
	}
} public class Main {
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		
		long x = scan.nextLong();
		scan.close();
		
		long ans = 0;
		long yen = 100;
		while(x > yen) {
			yen += yen/100;
			ans++;
		}
		
		System.out.println(ans);
	}
} Main
import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		
		long x = scan.nextLong();
		scan.close();
		
		long ans = 0;
		long yen = 100;
		while(x > yen) {
			yen += yen/100;
			ans++;
		}
		
		System.out.println(ans);
	}
}