import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner sc = new Scanner(System.in);
		Long X = sc.nextLong();

		int i = 0;
		int flag = 0;
		Long K = (long) 100;

		while(flag == 0) {
			if(K >= X) {
				flag = 1;
				i = i - 1;
			}
			K = (long)(1.01*K);
			i++;
		}

		System.out.println(i);
	}

} import java.util.Scanner; Scanner java.util public class Main {
	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner sc = new Scanner(System.in);
		Long X = sc.nextLong();

		int i = 0;
		int flag = 0;
		Long K = (long) 100;

		while(flag == 0) {
			if(K >= X) {
				flag = 1;
				i = i - 1;
			}
			K = (long)(1.01*K);
			i++;
		}

		System.out.println(i);
	}

} Main public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner sc = new Scanner(System.in);
		Long X = sc.nextLong();

		int i = 0;
		int flag = 0;
		Long K = (long) 100;

		while(flag == 0) {
			if(K >= X) {
				flag = 1;
				i = i - 1;
			}
			K = (long)(1.01*K);
			i++;
		}

		System.out.println(i);
	} main {
		// TODO 自動生成されたメソッド・スタブ
		Scanner sc = new Scanner(System.in);
		Long X = sc.nextLong();

		int i = 0;
		int flag = 0;
		Long K = (long) 100;

		while(flag == 0) {
			if(K >= X) {
				flag = 1;
				i = i - 1;
			}
			K = (long)(1.01*K);
			i++;
		}

		System.out.println(i);
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) Long X = sc.nextLong(); X sc.nextLong() sc.nextLong sc int i = 0; i 0 int flag = 0; flag 0 Long K = (long) 100; K (long) 100 while(flag == 0) {
			if(K >= X) {
				flag = 1;
				i = i - 1;
			}
			K = (long)(1.01*K);
			i++;
		} flag == 0 flag 0 {
			if(K >= X) {
				flag = 1;
				i = i - 1;
			}
			K = (long)(1.01*K);
			i++;
		} if(K >= X) {
				flag = 1;
				i = i - 1;
			} K >= X K X {
				flag = 1;
				i = i - 1;
			} flag = 1 flag 1 i = i - 1 i i - 1 i 1 K = (long)(1.01*K) K (long)(1.01*K) 1.01 K i++ i System.out.println(i) System.out.println System.out System System.out i String[] args args public class Main {
	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner sc = new Scanner(System.in);
		Long X = sc.nextLong();

		int i = 0;
		int flag = 0;
		Long K = (long) 100;

		while(flag == 0) {
			if(K >= X) {
				flag = 1;
				i = i - 1;
			}
			K = (long)(1.01*K);
			i++;
		}

		System.out.println(i);
	}

} public class Main {
	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner sc = new Scanner(System.in);
		Long X = sc.nextLong();

		int i = 0;
		int flag = 0;
		Long K = (long) 100;

		while(flag == 0) {
			if(K >= X) {
				flag = 1;
				i = i - 1;
			}
			K = (long)(1.01*K);
			i++;
		}

		System.out.println(i);
	}

} Main
import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		// TODO 自動生成されたメソッド・スタブ
		Scanner sc = new Scanner(System.in);
		Long X = sc.nextLong();

		int i = 0;
		int flag = 0;
		Long K = (long) 100;

		while(flag == 0) {
			if(K >= X) {
				flag = 1;
				i = i - 1;
			}
			K = (long)(1.01*K);
			i++;
		}

		System.out.println(i);
	}

}