import java.util.Scanner;

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

		long X = scan.nextLong();
		long m = 100;
		int ans = 0;

		while(true) {
			m *= 1.01;
			ans++;
			if(X <= m) {
				break;
			}
		}

		System.out.println(ans);

	}
} 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 m = 100;
		int ans = 0;

		while(true) {
			m *= 1.01;
			ans++;
			if(X <= m) {
				break;
			}
		}

		System.out.println(ans);

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

		long X = scan.nextLong();
		long m = 100;
		int ans = 0;

		while(true) {
			m *= 1.01;
			ans++;
			if(X <= m) {
				break;
			}
		}

		System.out.println(ans);

	} main {
		Scanner scan = new Scanner(System.in);

		long X = scan.nextLong();
		long m = 100;
		int ans = 0;

		while(true) {
			m *= 1.01;
			ans++;
			if(X <= m) {
				break;
			}
		}

		System.out.println(ans);

	} Scanner scan = new Scanner(System.in); scan new Scanner(System.in) long X = scan.nextLong(); X scan.nextLong() scan.nextLong scan long m = 100; m 100 int ans = 0; ans 0 while(true) {
			m *= 1.01;
			ans++;
			if(X <= m) {
				break;
			}
		} true {
			m *= 1.01;
			ans++;
			if(X <= m) {
				break;
			}
		} m *= 1.01 m 1.01 ans++ ans if(X <= m) {
				break;
			} X <= m X m {
				break;
			} break; System.out.println(ans) System.out.println System.out System System.out ans String[] args args public class Main {
	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);

		long X = scan.nextLong();
		long m = 100;
		int ans = 0;

		while(true) {
			m *= 1.01;
			ans++;
			if(X <= m) {
				break;
			}
		}

		System.out.println(ans);

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

		long X = scan.nextLong();
		long m = 100;
		int ans = 0;

		while(true) {
			m *= 1.01;
			ans++;
			if(X <= m) {
				break;
			}
		}

		System.out.println(ans);

	}
} 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 m = 100;
		int ans = 0;

		while(true) {
			m *= 1.01;
			ans++;
			if(X <= m) {
				break;
			}
		}

		System.out.println(ans);

	}
}