import java.util.Scanner;

public class Main {
	static long X;
	static int m=0;
	static long a=100;
	static boolean n=true;
	public static void main(String[]args) {
		Scanner sc=new Scanner(System.in);
		X=sc.nextLong();
		while(X>a) {
			m=m+1;
			a=a/100+a;
		}
		System.out.println(m);
	}
} import java.util.Scanner; Scanner java.util public class Main {
	static long X;
	static int m=0;
	static long a=100;
	static boolean n=true;
	public static void main(String[]args) {
		Scanner sc=new Scanner(System.in);
		X=sc.nextLong();
		while(X>a) {
			m=m+1;
			a=a/100+a;
		}
		System.out.println(m);
	}
} Main static long X; X static int m=0; m 0 static long a=100; a 100 static boolean n=true; n true public static void main(String[]args) {
		Scanner sc=new Scanner(System.in);
		X=sc.nextLong();
		while(X>a) {
			m=m+1;
			a=a/100+a;
		}
		System.out.println(m);
	} main {
		Scanner sc=new Scanner(System.in);
		X=sc.nextLong();
		while(X>a) {
			m=m+1;
			a=a/100+a;
		}
		System.out.println(m);
	} Scanner sc=new Scanner(System.in); sc new Scanner(System.in) X=sc.nextLong() X sc.nextLong() sc.nextLong sc while(X>a) {
			m=m+1;
			a=a/100+a;
		} X>a X a {
			m=m+1;
			a=a/100+a;
		} m=m+1 m m+1 m 1 a=a/100+a a a/100+a a/100 a 100 a System.out.println(m) System.out.println System.out System System.out m String[]args args public class Main {
	static long X;
	static int m=0;
	static long a=100;
	static boolean n=true;
	public static void main(String[]args) {
		Scanner sc=new Scanner(System.in);
		X=sc.nextLong();
		while(X>a) {
			m=m+1;
			a=a/100+a;
		}
		System.out.println(m);
	}
} public class Main {
	static long X;
	static int m=0;
	static long a=100;
	static boolean n=true;
	public static void main(String[]args) {
		Scanner sc=new Scanner(System.in);
		X=sc.nextLong();
		while(X>a) {
			m=m+1;
			a=a/100+a;
		}
		System.out.println(m);
	}
} Main
import java.util.Scanner;

public class Main {
	static long X;
	static int m=0;
	static long a=100;
	static boolean n=true;
	public static void main(String[]args) {
		Scanner sc=new Scanner(System.in);
		X=sc.nextLong();
		while(X>a) {
			m=m+1;
			a=a/100+a;
		}
		System.out.println(m);
	}
}
