import java.util.Scanner;

public class Main {
    static long x, ans;

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner in = new Scanner(System.in);
        x = in.nextLong();
        int n = 0;
        for (long i = 100; i < x;) {
            long a = i / 100;
            i += a;
            n++;
        }
        System.out.println(n);
    }
} import java.util.Scanner; Scanner java.util public class Main {
    static long x, ans;

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner in = new Scanner(System.in);
        x = in.nextLong();
        int n = 0;
        for (long i = 100; i < x;) {
            long a = i / 100;
            i += a;
            n++;
        }
        System.out.println(n);
    }
} Main static long x x ans; ans public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner in = new Scanner(System.in);
        x = in.nextLong();
        int n = 0;
        for (long i = 100; i < x;) {
            long a = i / 100;
            i += a;
            n++;
        }
        System.out.println(n);
    } main {
        // TODO Auto-generated method stub
        Scanner in = new Scanner(System.in);
        x = in.nextLong();
        int n = 0;
        for (long i = 100; i < x;) {
            long a = i / 100;
            i += a;
            n++;
        }
        System.out.println(n);
    } Scanner in = new Scanner(System.in); in new Scanner(System.in) x = in.nextLong() x in.nextLong() in.nextLong in int n = 0; n 0 for (long i = 100; i < x;) {
            long a = i / 100;
            i += a;
            n++;
        } long i = 100; long i = 100; i 100 i < x i x {
            long a = i / 100;
            i += a;
            n++;
        } {
            long a = i / 100;
            i += a;
            n++;
        } long a = i / 100; a i / 100 i 100 i += a i a n++ n System.out.println(n) System.out.println System.out System System.out n String[] args args public class Main {
    static long x, ans;

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner in = new Scanner(System.in);
        x = in.nextLong();
        int n = 0;
        for (long i = 100; i < x;) {
            long a = i / 100;
            i += a;
            n++;
        }
        System.out.println(n);
    }
} public class Main {
    static long x, ans;

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner in = new Scanner(System.in);
        x = in.nextLong();
        int n = 0;
        for (long i = 100; i < x;) {
            long a = i / 100;
            i += a;
            n++;
        }
        System.out.println(n);
    }
} Main
import java.util.Scanner;

public class Main {
    static long x, ans;

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner in = new Scanner(System.in);
        x = in.nextLong();
        int n = 0;
        for (long i = 100; i < x;) {
            long a = i / 100;
            i += a;
            n++;
        }
        System.out.println(n);
    }
}
