import java.util.*;

public class Main{
    public static void main(String[] args){
	Scanner sc = new Scanner(System.in);
	long X = sc.nextLong();
	long i = 100;
    int years = 0;
	while(i < X){
      i += i / 100L;
      years++;
    }
      System.out.println(years);
	}
} 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 i = 100;
    int years = 0;
	while(i < X){
      i += i / 100L;
      years++;
    }
      System.out.println(years);
	}
} Main public static void main(String[] args){
	Scanner sc = new Scanner(System.in);
	long X = sc.nextLong();
	long i = 100;
    int years = 0;
	while(i < X){
      i += i / 100L;
      years++;
    }
      System.out.println(years);
	} main {
	Scanner sc = new Scanner(System.in);
	long X = sc.nextLong();
	long i = 100;
    int years = 0;
	while(i < X){
      i += i / 100L;
      years++;
    }
      System.out.println(years);
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) long X = sc.nextLong(); X sc.nextLong() sc.nextLong sc long i = 100; i 100 int years = 0; years 0 while(i < X){
      i += i / 100L;
      years++;
    } i < X i X {
      i += i / 100L;
      years++;
    } i += i / 100L i i / 100L i 100L years++ years System.out.println(years) System.out.println System.out System System.out years String[] args args public class Main{
    public static void main(String[] args){
	Scanner sc = new Scanner(System.in);
	long X = sc.nextLong();
	long i = 100;
    int years = 0;
	while(i < X){
      i += i / 100L;
      years++;
    }
      System.out.println(years);
	}
} public class Main{
    public static void main(String[] args){
	Scanner sc = new Scanner(System.in);
	long X = sc.nextLong();
	long i = 100;
    int years = 0;
	while(i < X){
      i += i / 100L;
      years++;
    }
      System.out.println(years);
	}
} Main
import java.util.*;

public class Main{
    public static void main(String[] args){
	Scanner sc = new Scanner(System.in);
	long X = sc.nextLong();
	long i = 100;
    int years = 0;
	while(i < X){
      i += i / 100L;
      years++;
    }
      System.out.println(years);
	}
}