import java.util.*;
import java.lang.*;
public class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);

		long X = sc.nextLong();
		int count = 0;
		long A = 100;
		for( int i=0; i<4000; i++ ){
			A = A+A/100;
			count++;
			if( A>=X ){
				break;
			}
		}
		System.out.println(count);
	}
} import java.util.*; util.* java import java.lang.*; lang.* java public class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);

		long X = sc.nextLong();
		int count = 0;
		long A = 100;
		for( int i=0; i<4000; i++ ){
			A = A+A/100;
			count++;
			if( A>=X ){
				break;
			}
		}
		System.out.println(count);
	}
} Main public static void main(String[] args){
		Scanner sc = new Scanner(System.in);

		long X = sc.nextLong();
		int count = 0;
		long A = 100;
		for( int i=0; i<4000; i++ ){
			A = A+A/100;
			count++;
			if( A>=X ){
				break;
			}
		}
		System.out.println(count);
	} main {
		Scanner sc = new Scanner(System.in);

		long X = sc.nextLong();
		int count = 0;
		long A = 100;
		for( int i=0; i<4000; i++ ){
			A = A+A/100;
			count++;
			if( A>=X ){
				break;
			}
		}
		System.out.println(count);
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) long X = sc.nextLong(); X sc.nextLong() sc.nextLong sc int count = 0; count 0 long A = 100; A 100 for( int i=0; i<4000; i++ ){
			A = A+A/100;
			count++;
			if( A>=X ){
				break;
			}
		} int i=0; int i=0; i 0 i<4000 i 4000 i++ i++ i {
			A = A+A/100;
			count++;
			if( A>=X ){
				break;
			}
		} {
			A = A+A/100;
			count++;
			if( A>=X ){
				break;
			}
		} A = A+A/100 A A+A/100 A A/100 A 100 count++ count if( A>=X ){
				break;
			} A>=X A X {
				break;
			} break; System.out.println(count) System.out.println System.out System System.out count String[] args args public class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);

		long X = sc.nextLong();
		int count = 0;
		long A = 100;
		for( int i=0; i<4000; i++ ){
			A = A+A/100;
			count++;
			if( A>=X ){
				break;
			}
		}
		System.out.println(count);
	}
} public class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);

		long X = sc.nextLong();
		int count = 0;
		long A = 100;
		for( int i=0; i<4000; i++ ){
			A = A+A/100;
			count++;
			if( A>=X ){
				break;
			}
		}
		System.out.println(count);
	}
} Main
import java.util.*;
import java.lang.*;
public class Main{
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);

		long X = sc.nextLong();
		int count = 0;
		long A = 100;
		for( int i=0; i<4000; i++ ){
			A = A+A/100;
			count++;
			if( A>=X ){
				break;
			}
		}
		System.out.println(count);
	}
}