import java.util.*;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		double X = sc.nextDouble();

		int cnt = 0;
		double tmp = 100.0;
		while (tmp<X) {
			cnt++;
			tmp *= 1.01;
			tmp = Math.floor(tmp);
		}
		System.out.println(cnt);
	}
} import java.util.*; util.* java public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		double X = sc.nextDouble();

		int cnt = 0;
		double tmp = 100.0;
		while (tmp<X) {
			cnt++;
			tmp *= 1.01;
			tmp = Math.floor(tmp);
		}
		System.out.println(cnt);
	}
} Main public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		double X = sc.nextDouble();

		int cnt = 0;
		double tmp = 100.0;
		while (tmp<X) {
			cnt++;
			tmp *= 1.01;
			tmp = Math.floor(tmp);
		}
		System.out.println(cnt);
	} main {
		Scanner sc = new Scanner(System.in);
		double X = sc.nextDouble();

		int cnt = 0;
		double tmp = 100.0;
		while (tmp<X) {
			cnt++;
			tmp *= 1.01;
			tmp = Math.floor(tmp);
		}
		System.out.println(cnt);
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) double X = sc.nextDouble(); X sc.nextDouble() sc.nextDouble sc int cnt = 0; cnt 0 double tmp = 100.0; tmp 100.0 while (tmp<X) {
			cnt++;
			tmp *= 1.01;
			tmp = Math.floor(tmp);
		} tmp<X tmp X {
			cnt++;
			tmp *= 1.01;
			tmp = Math.floor(tmp);
		} cnt++ cnt tmp *= 1.01 tmp 1.01 tmp = Math.floor(tmp) tmp Math.floor(tmp) Math.floor Math tmp System.out.println(cnt) System.out.println System.out System System.out cnt String[] args args public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		double X = sc.nextDouble();

		int cnt = 0;
		double tmp = 100.0;
		while (tmp<X) {
			cnt++;
			tmp *= 1.01;
			tmp = Math.floor(tmp);
		}
		System.out.println(cnt);
	}
} public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		double X = sc.nextDouble();

		int cnt = 0;
		double tmp = 100.0;
		while (tmp<X) {
			cnt++;
			tmp *= 1.01;
			tmp = Math.floor(tmp);
		}
		System.out.println(cnt);
	}
} Main
import java.util.*;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		double X = sc.nextDouble();

		int cnt = 0;
		double tmp = 100.0;
		while (tmp<X) {
			cnt++;
			tmp *= 1.01;
			tmp = Math.floor(tmp);
		}
		System.out.println(cnt);
	}
}