//b_1_percent
import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long x = sc.nextLong();
		long yen_at_bank = 100;
		int year = 0;
		
		
		while(true) {
			year++;
			yen_at_bank = yen_at_bank + yen_at_bank / 100;
			if(yen_at_bank >= x) {
				System.out.println(year);
				return;
			}
		}
	}
} 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 yen_at_bank = 100;
		int year = 0;
		
		
		while(true) {
			year++;
			yen_at_bank = yen_at_bank + yen_at_bank / 100;
			if(yen_at_bank >= x) {
				System.out.println(year);
				return;
			}
		}
	}
} Main public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long x = sc.nextLong();
		long yen_at_bank = 100;
		int year = 0;
		
		
		while(true) {
			year++;
			yen_at_bank = yen_at_bank + yen_at_bank / 100;
			if(yen_at_bank >= x) {
				System.out.println(year);
				return;
			}
		}
	} main {
		Scanner sc = new Scanner(System.in);
		long x = sc.nextLong();
		long yen_at_bank = 100;
		int year = 0;
		
		
		while(true) {
			year++;
			yen_at_bank = yen_at_bank + yen_at_bank / 100;
			if(yen_at_bank >= x) {
				System.out.println(year);
				return;
			}
		}
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) long x = sc.nextLong(); x sc.nextLong() sc.nextLong sc long yen_at_bank = 100; yen_at_bank 100 int year = 0; year 0 while(true) {
			year++;
			yen_at_bank = yen_at_bank + yen_at_bank / 100;
			if(yen_at_bank >= x) {
				System.out.println(year);
				return;
			}
		} true {
			year++;
			yen_at_bank = yen_at_bank + yen_at_bank / 100;
			if(yen_at_bank >= x) {
				System.out.println(year);
				return;
			}
		} year++ year yen_at_bank = yen_at_bank + yen_at_bank / 100 yen_at_bank yen_at_bank + yen_at_bank / 100 yen_at_bank yen_at_bank / 100 yen_at_bank 100 if(yen_at_bank >= x) {
				System.out.println(year);
				return;
			} yen_at_bank >= x yen_at_bank x {
				System.out.println(year);
				return;
			} System.out.println(year) System.out.println System.out System System.out year return; String[] args args public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long x = sc.nextLong();
		long yen_at_bank = 100;
		int year = 0;
		
		
		while(true) {
			year++;
			yen_at_bank = yen_at_bank + yen_at_bank / 100;
			if(yen_at_bank >= x) {
				System.out.println(year);
				return;
			}
		}
	}
} public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long x = sc.nextLong();
		long yen_at_bank = 100;
		int year = 0;
		
		
		while(true) {
			year++;
			yen_at_bank = yen_at_bank + yen_at_bank / 100;
			if(yen_at_bank >= x) {
				System.out.println(year);
				return;
			}
		}
	}
} Main
//b_1_percent
import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long x = sc.nextLong();
		long yen_at_bank = 100;
		int year = 0;
		
		
		while(true) {
			year++;
			yen_at_bank = yen_at_bank + yen_at_bank / 100;
			if(yen_at_bank >= x) {
				System.out.println(year);
				return;
			}
		}
	}
}