import java.util.*;

public class Main {
public static void main(String[] args) {
		
		Scanner keyboard = new Scanner(System.in); 
		
		long X= keyboard.nextLong();
		int ans = 0;
		long x = 100;

		while(x < X ) {
			x += x/100;
			ans++;
		}
		
		System.out.println(ans);
		keyboard.close();	
		
	}
} import java.util.*; util.* java public class Main {
public static void main(String[] args) {
		
		Scanner keyboard = new Scanner(System.in); 
		
		long X= keyboard.nextLong();
		int ans = 0;
		long x = 100;

		while(x < X ) {
			x += x/100;
			ans++;
		}
		
		System.out.println(ans);
		keyboard.close();	
		
	}
} Main public static void main(String[] args) {
		
		Scanner keyboard = new Scanner(System.in); 
		
		long X= keyboard.nextLong();
		int ans = 0;
		long x = 100;

		while(x < X ) {
			x += x/100;
			ans++;
		}
		
		System.out.println(ans);
		keyboard.close();	
		
	} main {
		
		Scanner keyboard = new Scanner(System.in); 
		
		long X= keyboard.nextLong();
		int ans = 0;
		long x = 100;

		while(x < X ) {
			x += x/100;
			ans++;
		}
		
		System.out.println(ans);
		keyboard.close();	
		
	} Scanner keyboard = new Scanner(System.in); keyboard new Scanner(System.in) long X= keyboard.nextLong(); X keyboard.nextLong() keyboard.nextLong keyboard int ans = 0; ans 0 long x = 100; x 100 while(x < X ) {
			x += x/100;
			ans++;
		} x < X x X {
			x += x/100;
			ans++;
		} x += x/100 x x/100 x 100 ans++ ans System.out.println(ans) System.out.println System.out System System.out ans keyboard.close() keyboard.close keyboard String[] args args public class Main {
public static void main(String[] args) {
		
		Scanner keyboard = new Scanner(System.in); 
		
		long X= keyboard.nextLong();
		int ans = 0;
		long x = 100;

		while(x < X ) {
			x += x/100;
			ans++;
		}
		
		System.out.println(ans);
		keyboard.close();	
		
	}
} public class Main {
public static void main(String[] args) {
		
		Scanner keyboard = new Scanner(System.in); 
		
		long X= keyboard.nextLong();
		int ans = 0;
		long x = 100;

		while(x < X ) {
			x += x/100;
			ans++;
		}
		
		System.out.println(ans);
		keyboard.close();	
		
	}
} Main
import java.util.*;

public class Main {
public static void main(String[] args) {
		
		Scanner keyboard = new Scanner(System.in); 
		
		long X= keyboard.nextLong();
		int ans = 0;
		long x = 100;

		while(x < X ) {
			x += x/100;
			ans++;
		}
		
		System.out.println(ans);
		keyboard.close();	
		
	}
}
