import java.util.*;

public class Main{
  public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long X = sc.nextLong();
		long bank = 100;
		long count = 0;
		for(long i = bank;i < X;bank += bank / 100,count++) {
			if(bank >= X) {
				System.out.println(count);
				break;
			}
		}
	}
} import java.util.*; util.* java public class Main{
  public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long X = sc.nextLong();
		long bank = 100;
		long count = 0;
		for(long i = bank;i < X;bank += bank / 100,count++) {
			if(bank >= X) {
				System.out.println(count);
				break;
			}
		}
	}
} Main public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long X = sc.nextLong();
		long bank = 100;
		long count = 0;
		for(long i = bank;i < X;bank += bank / 100,count++) {
			if(bank >= X) {
				System.out.println(count);
				break;
			}
		}
	} main {
		Scanner sc = new Scanner(System.in);
		long X = sc.nextLong();
		long bank = 100;
		long count = 0;
		for(long i = bank;i < X;bank += bank / 100,count++) {
			if(bank >= X) {
				System.out.println(count);
				break;
			}
		}
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) long X = sc.nextLong(); X sc.nextLong() sc.nextLong sc long bank = 100; bank 100 long count = 0; count 0 for(long i = bank;i < X;bank += bank / 100,count++) {
			if(bank >= X) {
				System.out.println(count);
				break;
			}
		} long i = bank; long i = bank; i bank i < X i X bank += bank / 100,count++ bank += bank / 100 bank bank / 100 bank 100 count++ count {
			if(bank >= X) {
				System.out.println(count);
				break;
			}
		} {
			if(bank >= X) {
				System.out.println(count);
				break;
			}
		} if(bank >= X) {
				System.out.println(count);
				break;
			} bank >= X bank X {
				System.out.println(count);
				break;
			} System.out.println(count) System.out.println System.out System System.out count break; String[] args args public class Main{
  public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long X = sc.nextLong();
		long bank = 100;
		long count = 0;
		for(long i = bank;i < X;bank += bank / 100,count++) {
			if(bank >= X) {
				System.out.println(count);
				break;
			}
		}
	}
} public class Main{
  public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long X = sc.nextLong();
		long bank = 100;
		long count = 0;
		for(long i = bank;i < X;bank += bank / 100,count++) {
			if(bank >= X) {
				System.out.println(count);
				break;
			}
		}
	}
} Main
import java.util.*;

public class Main{
  public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		long X = sc.nextLong();
		long bank = 100;
		long count = 0;
		for(long i = bank;i < X;bank += bank / 100,count++) {
			if(bank >= X) {
				System.out.println(count);
				break;
			}
		}
	}
}