import java.util.*;

public class Main {
	public static void main(String[] args) {
		Scanner input = new Scanner(System.in);
		long X = input.nextLong();
		long yokin = 100;
		int i=0;
		
		for(i=0;yokin<X;i++) {
			yokin+= (long)(yokin*0.01);
		}
		System.out.println(i);
	}
} import java.util.*; util.* java public class Main {
	public static void main(String[] args) {
		Scanner input = new Scanner(System.in);
		long X = input.nextLong();
		long yokin = 100;
		int i=0;
		
		for(i=0;yokin<X;i++) {
			yokin+= (long)(yokin*0.01);
		}
		System.out.println(i);
	}
} Main public static void main(String[] args) {
		Scanner input = new Scanner(System.in);
		long X = input.nextLong();
		long yokin = 100;
		int i=0;
		
		for(i=0;yokin<X;i++) {
			yokin+= (long)(yokin*0.01);
		}
		System.out.println(i);
	} main {
		Scanner input = new Scanner(System.in);
		long X = input.nextLong();
		long yokin = 100;
		int i=0;
		
		for(i=0;yokin<X;i++) {
			yokin+= (long)(yokin*0.01);
		}
		System.out.println(i);
	} Scanner input = new Scanner(System.in); input new Scanner(System.in) long X = input.nextLong(); X input.nextLong() input.nextLong input long yokin = 100; yokin 100 int i=0; i 0 for(i=0;yokin<X;i++) {
			yokin+= (long)(yokin*0.01);
		} i=0; i=0 i 0 yokin<X yokin X i++ i++ i {
			yokin+= (long)(yokin*0.01);
		} {
			yokin+= (long)(yokin*0.01);
		} yokin+= (long)(yokin*0.01) yokin (long)(yokin*0.01) yokin 0.01 System.out.println(i) System.out.println System.out System System.out i String[] args args public class Main {
	public static void main(String[] args) {
		Scanner input = new Scanner(System.in);
		long X = input.nextLong();
		long yokin = 100;
		int i=0;
		
		for(i=0;yokin<X;i++) {
			yokin+= (long)(yokin*0.01);
		}
		System.out.println(i);
	}
} public class Main {
	public static void main(String[] args) {
		Scanner input = new Scanner(System.in);
		long X = input.nextLong();
		long yokin = 100;
		int i=0;
		
		for(i=0;yokin<X;i++) {
			yokin+= (long)(yokin*0.01);
		}
		System.out.println(i);
	}
} Main
import java.util.*;

public class Main {
	public static void main(String[] args) {
		Scanner input = new Scanner(System.in);
		long X = input.nextLong();
		long yokin = 100;
		int i=0;
		
		for(i=0;yokin<X;i++) {
			yokin+= (long)(yokin*0.01);
		}
		System.out.println(i);
	}
}
