import java.util.Scanner;
public class Main {

	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		long x = scan.nextLong();
		long a = 100;
		int count = 0;
		boolean b = true;
		
		while(b) {
			a += a / 100;
			count++;
			if(a >= x) {
				b = false;
			}
		}
		System.out.println(count);

	}

} import java.util.Scanner; Scanner java.util public class Main {

	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		long x = scan.nextLong();
		long a = 100;
		int count = 0;
		boolean b = true;
		
		while(b) {
			a += a / 100;
			count++;
			if(a >= x) {
				b = false;
			}
		}
		System.out.println(count);

	}

} Main public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		long x = scan.nextLong();
		long a = 100;
		int count = 0;
		boolean b = true;
		
		while(b) {
			a += a / 100;
			count++;
			if(a >= x) {
				b = false;
			}
		}
		System.out.println(count);

	} main {
		Scanner scan = new Scanner(System.in);
		long x = scan.nextLong();
		long a = 100;
		int count = 0;
		boolean b = true;
		
		while(b) {
			a += a / 100;
			count++;
			if(a >= x) {
				b = false;
			}
		}
		System.out.println(count);

	} Scanner scan = new Scanner(System.in); scan new Scanner(System.in) long x = scan.nextLong(); x scan.nextLong() scan.nextLong scan long a = 100; a 100 int count = 0; count 0 boolean b = true; b true while(b) {
			a += a / 100;
			count++;
			if(a >= x) {
				b = false;
			}
		} b {
			a += a / 100;
			count++;
			if(a >= x) {
				b = false;
			}
		} a += a / 100 a a / 100 a 100 count++ count if(a >= x) {
				b = false;
			} a >= x a x {
				b = false;
			} b = false b false 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 scan = new Scanner(System.in);
		long x = scan.nextLong();
		long a = 100;
		int count = 0;
		boolean b = true;
		
		while(b) {
			a += a / 100;
			count++;
			if(a >= x) {
				b = false;
			}
		}
		System.out.println(count);

	}

} public class Main {

	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		long x = scan.nextLong();
		long a = 100;
		int count = 0;
		boolean b = true;
		
		while(b) {
			a += a / 100;
			count++;
			if(a >= x) {
				b = false;
			}
		}
		System.out.println(count);

	}

} Main
import java.util.Scanner;
public class Main {

	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		long x = scan.nextLong();
		long a = 100;
		int count = 0;
		boolean b = true;
		
		while(b) {
			a += a / 100;
			count++;
			if(a >= x) {
				b = false;
			}
		}
		System.out.println(count);

	}

}
