import java.util.*;

class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		long a = sc.nextLong();
		long ret = 100;
		for(int i = 1;;i++){
			ret += ret * 0.01;
			if(ret >= a){
				System.out.print(i);
				break;
			}
		}
	}
} import java.util.*; util.* java class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		long a = sc.nextLong();
		long ret = 100;
		for(int i = 1;;i++){
			ret += ret * 0.01;
			if(ret >= a){
				System.out.print(i);
				break;
			}
		}
	}
} Main public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		long a = sc.nextLong();
		long ret = 100;
		for(int i = 1;;i++){
			ret += ret * 0.01;
			if(ret >= a){
				System.out.print(i);
				break;
			}
		}
	} main {
		Scanner sc = new Scanner(System.in);
		long a = sc.nextLong();
		long ret = 100;
		for(int i = 1;;i++){
			ret += ret * 0.01;
			if(ret >= a){
				System.out.print(i);
				break;
			}
		}
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) long a = sc.nextLong(); a sc.nextLong() sc.nextLong sc long ret = 100; ret 100 for(int i = 1;;i++){
			ret += ret * 0.01;
			if(ret >= a){
				System.out.print(i);
				break;
			}
		} int i = 1; int i = 1; i 1 i++ i++ i {
			ret += ret * 0.01;
			if(ret >= a){
				System.out.print(i);
				break;
			}
		} {
			ret += ret * 0.01;
			if(ret >= a){
				System.out.print(i);
				break;
			}
		} ret += ret * 0.01 ret ret * 0.01 ret 0.01 if(ret >= a){
				System.out.print(i);
				break;
			} ret >= a ret a {
				System.out.print(i);
				break;
			} System.out.print(i) System.out.print System.out System System.out i break; String[] args args
import java.util.*;

class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		long a = sc.nextLong();
		long ret = 100;
		for(int i = 1;;i++){
			ret += ret * 0.01;
			if(ret >= a){
				System.out.print(i);
				break;
			}
		}
	}
}