import java.util.Scanner;

public class Main{
	public static void main(String[] args)throws Exception {
		Scanner scan = new Scanner(System.in);
		long money = scan.nextLong();
		long year = 0;
		for(long num = 100;num < money;num = num + num/100) {
			year ++;
		}
		System.out.println(year);

		scan.close();
	}
} import java.util.Scanner; Scanner java.util public class Main{
	public static void main(String[] args)throws Exception {
		Scanner scan = new Scanner(System.in);
		long money = scan.nextLong();
		long year = 0;
		for(long num = 100;num < money;num = num + num/100) {
			year ++;
		}
		System.out.println(year);

		scan.close();
	}
} Main public static void main(String[] args)throws Exception {
		Scanner scan = new Scanner(System.in);
		long money = scan.nextLong();
		long year = 0;
		for(long num = 100;num < money;num = num + num/100) {
			year ++;
		}
		System.out.println(year);

		scan.close();
	} main {
		Scanner scan = new Scanner(System.in);
		long money = scan.nextLong();
		long year = 0;
		for(long num = 100;num < money;num = num + num/100) {
			year ++;
		}
		System.out.println(year);

		scan.close();
	} Scanner scan = new Scanner(System.in); scan new Scanner(System.in) long money = scan.nextLong(); money scan.nextLong() scan.nextLong scan long year = 0; year 0 for(long num = 100;num < money;num = num + num/100) {
			year ++;
		} long num = 100; long num = 100; num 100 num < money num money num = num + num/100 num = num + num/100 num num + num/100 num num/100 num 100 {
			year ++;
		} {
			year ++;
		} year ++ year System.out.println(year) System.out.println System.out System System.out year scan.close() scan.close scan String[] args args public class Main{
	public static void main(String[] args)throws Exception {
		Scanner scan = new Scanner(System.in);
		long money = scan.nextLong();
		long year = 0;
		for(long num = 100;num < money;num = num + num/100) {
			year ++;
		}
		System.out.println(year);

		scan.close();
	}
} public class Main{
	public static void main(String[] args)throws Exception {
		Scanner scan = new Scanner(System.in);
		long money = scan.nextLong();
		long year = 0;
		for(long num = 100;num < money;num = num + num/100) {
			year ++;
		}
		System.out.println(year);

		scan.close();
	}
} Main
import java.util.Scanner;

public class Main{
	public static void main(String[] args)throws Exception {
		Scanner scan = new Scanner(System.in);
		long money = scan.nextLong();
		long year = 0;
		for(long num = 100;num < money;num = num + num/100) {
			year ++;
		}
		System.out.println(year);

		scan.close();
	}
}