import java.util.*;

public class Main {
    public static void main(String[] args){
        Scanner in = new Scanner(System.in);
        long k = Long.parseLong(in.nextLine());
        // String[] tmp = in.nextLine().trim().split("\\s");
        // int a = Integer.parseInt(tmp[0]);
        // int b = Integer.parseInt(tmp[1]);
        in.close();
        int i = 0;
        long base = 100;
        while(base < k){
            long inc = (long)(base * 0.01);
            base += inc;
            i++;
        }
        System.out.println(i);
    }
} import java.util.*; util.* java public class Main {
    public static void main(String[] args){
        Scanner in = new Scanner(System.in);
        long k = Long.parseLong(in.nextLine());
        // String[] tmp = in.nextLine().trim().split("\\s");
        // int a = Integer.parseInt(tmp[0]);
        // int b = Integer.parseInt(tmp[1]);
        in.close();
        int i = 0;
        long base = 100;
        while(base < k){
            long inc = (long)(base * 0.01);
            base += inc;
            i++;
        }
        System.out.println(i);
    }
} Main public static void main(String[] args){
        Scanner in = new Scanner(System.in);
        long k = Long.parseLong(in.nextLine());
        // String[] tmp = in.nextLine().trim().split("\\s");
        // int a = Integer.parseInt(tmp[0]);
        // int b = Integer.parseInt(tmp[1]);
        in.close();
        int i = 0;
        long base = 100;
        while(base < k){
            long inc = (long)(base * 0.01);
            base += inc;
            i++;
        }
        System.out.println(i);
    } main {
        Scanner in = new Scanner(System.in);
        long k = Long.parseLong(in.nextLine());
        // String[] tmp = in.nextLine().trim().split("\\s");
        // int a = Integer.parseInt(tmp[0]);
        // int b = Integer.parseInt(tmp[1]);
        in.close();
        int i = 0;
        long base = 100;
        while(base < k){
            long inc = (long)(base * 0.01);
            base += inc;
            i++;
        }
        System.out.println(i);
    } Scanner in = new Scanner(System.in); in new Scanner(System.in) long k = Long.parseLong(in.nextLine()); k Long.parseLong(in.nextLine()) Long.parseLong Long in.nextLine() in.nextLine in in.close() in.close in int i = 0; i 0 long base = 100; base 100 while(base < k){
            long inc = (long)(base * 0.01);
            base += inc;
            i++;
        } base < k base k {
            long inc = (long)(base * 0.01);
            base += inc;
            i++;
        } long inc = (long)(base * 0.01); inc (long)(base * 0.01) base 0.01 base += inc base inc 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){
        Scanner in = new Scanner(System.in);
        long k = Long.parseLong(in.nextLine());
        // String[] tmp = in.nextLine().trim().split("\\s");
        // int a = Integer.parseInt(tmp[0]);
        // int b = Integer.parseInt(tmp[1]);
        in.close();
        int i = 0;
        long base = 100;
        while(base < k){
            long inc = (long)(base * 0.01);
            base += inc;
            i++;
        }
        System.out.println(i);
    }
} public class Main {
    public static void main(String[] args){
        Scanner in = new Scanner(System.in);
        long k = Long.parseLong(in.nextLine());
        // String[] tmp = in.nextLine().trim().split("\\s");
        // int a = Integer.parseInt(tmp[0]);
        // int b = Integer.parseInt(tmp[1]);
        in.close();
        int i = 0;
        long base = 100;
        while(base < k){
            long inc = (long)(base * 0.01);
            base += inc;
            i++;
        }
        System.out.println(i);
    }
} Main
import java.util.*;

public class Main {
    public static void main(String[] args){
        Scanner in = new Scanner(System.in);
        long k = Long.parseLong(in.nextLine());
        // String[] tmp = in.nextLine().trim().split("\\s");
        // int a = Integer.parseInt(tmp[0]);
        // int b = Integer.parseInt(tmp[1]);
        in.close();
        int i = 0;
        long base = 100;
        while(base < k){
            long inc = (long)(base * 0.01);
            base += inc;
            i++;
        }
        System.out.println(i);
    }
}