import java.util.Scanner;
public class Main {
 
	public static void main(String[] args) {
		Scanner stdIn =new Scanner(System.in);
		long X =stdIn.nextLong();
		long Y=100;
		long i;
		
		for(i=0;Y<X;i++) {
			Y=(long) (Y*1.01);
			Y=Y/1;
		}
		System.out.println(i);
		
		
	}
 
} import java.util.Scanner; Scanner java.util public class Main {
 
	public static void main(String[] args) {
		Scanner stdIn =new Scanner(System.in);
		long X =stdIn.nextLong();
		long Y=100;
		long i;
		
		for(i=0;Y<X;i++) {
			Y=(long) (Y*1.01);
			Y=Y/1;
		}
		System.out.println(i);
		
		
	}
 
} Main public static void main(String[] args) {
		Scanner stdIn =new Scanner(System.in);
		long X =stdIn.nextLong();
		long Y=100;
		long i;
		
		for(i=0;Y<X;i++) {
			Y=(long) (Y*1.01);
			Y=Y/1;
		}
		System.out.println(i);
		
		
	} main {
		Scanner stdIn =new Scanner(System.in);
		long X =stdIn.nextLong();
		long Y=100;
		long i;
		
		for(i=0;Y<X;i++) {
			Y=(long) (Y*1.01);
			Y=Y/1;
		}
		System.out.println(i);
		
		
	} Scanner stdIn =new Scanner(System.in); stdIn new Scanner(System.in) long X =stdIn.nextLong(); X stdIn.nextLong() stdIn.nextLong stdIn long Y=100; Y 100 long i; i for(i=0;Y<X;i++) {
			Y=(long) (Y*1.01);
			Y=Y/1;
		} i=0; i=0 i 0 Y<X Y X i++ i++ i {
			Y=(long) (Y*1.01);
			Y=Y/1;
		} {
			Y=(long) (Y*1.01);
			Y=Y/1;
		} Y=(long) (Y*1.01) Y (long) (Y*1.01) Y 1.01 Y=Y/1 Y Y/1 Y 1 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 stdIn =new Scanner(System.in);
		long X =stdIn.nextLong();
		long Y=100;
		long i;
		
		for(i=0;Y<X;i++) {
			Y=(long) (Y*1.01);
			Y=Y/1;
		}
		System.out.println(i);
		
		
	}
 
} public class Main {
 
	public static void main(String[] args) {
		Scanner stdIn =new Scanner(System.in);
		long X =stdIn.nextLong();
		long Y=100;
		long i;
		
		for(i=0;Y<X;i++) {
			Y=(long) (Y*1.01);
			Y=Y/1;
		}
		System.out.println(i);
		
		
	}
 
} Main
import java.util.Scanner;
public class Main {
 
	public static void main(String[] args) {
		Scanner stdIn =new Scanner(System.in);
		long X =stdIn.nextLong();
		long Y=100;
		long i;
		
		for(i=0;Y<X;i++) {
			Y=(long) (Y*1.01);
			Y=Y/1;
		}
		System.out.println(i);
		
		
	}
 
}