import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);

		long X = sc.nextLong();
		long money = 100L;
		long count = 0L;

		for (; ;) {
			count += 1;
			money *= 1.01;

			if (money >= X) {
				break;
			}
		}

		System.out.println(count);
	}

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

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);

		long X = sc.nextLong();
		long money = 100L;
		long count = 0L;

		for (; ;) {
			count += 1;
			money *= 1.01;

			if (money >= X) {
				break;
			}
		}

		System.out.println(count);
	}

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

		long X = sc.nextLong();
		long money = 100L;
		long count = 0L;

		for (; ;) {
			count += 1;
			money *= 1.01;

			if (money >= X) {
				break;
			}
		}

		System.out.println(count);
	} main {
		Scanner sc = new Scanner(System.in);

		long X = sc.nextLong();
		long money = 100L;
		long count = 0L;

		for (; ;) {
			count += 1;
			money *= 1.01;

			if (money >= 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 long money = 100L; money 100L long count = 0L; count 0L for (; ;) {
			count += 1;
			money *= 1.01;

			if (money >= X) {
				break;
			}
		} ; {
			count += 1;
			money *= 1.01;

			if (money >= X) {
				break;
			}
		} {
			count += 1;
			money *= 1.01;

			if (money >= X) {
				break;
			}
		} count += 1 count 1 money *= 1.01 money 1.01 if (money >= X) {
				break;
			} money >= X money 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();
		long money = 100L;
		long count = 0L;

		for (; ;) {
			count += 1;
			money *= 1.01;

			if (money >= 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();
		long money = 100L;
		long count = 0L;

		for (; ;) {
			count += 1;
			money *= 1.01;

			if (money >= X) {
				break;
			}
		}

		System.out.println(count);
	}

} Main
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);

		long X = sc.nextLong();
		long money = 100L;
		long count = 0L;

		for (; ;) {
			count += 1;
			money *= 1.01;

			if (money >= X) {
				break;
			}
		}

		System.out.println(count);
	}

}
