import java.io.*;
public class Main {
    public static void main(String[] args) throws IOException{
        long X=0;
        int i=0;
        long n = 100;
        double k = 0;
        BufferedReader r = new BufferedReader(new InputStreamReader(System.in));
        X = Long.parseLong(r.readLine());
        do{
            i++;
            k = Math.ceil((double)(n/100));
            n += (long)k;
        }while(n<X);
        System.out.println(i);
    }
} import java.io.*; io.* java public class Main {
    public static void main(String[] args) throws IOException{
        long X=0;
        int i=0;
        long n = 100;
        double k = 0;
        BufferedReader r = new BufferedReader(new InputStreamReader(System.in));
        X = Long.parseLong(r.readLine());
        do{
            i++;
            k = Math.ceil((double)(n/100));
            n += (long)k;
        }while(n<X);
        System.out.println(i);
    }
} Main public static void main(String[] args) throws IOException{
        long X=0;
        int i=0;
        long n = 100;
        double k = 0;
        BufferedReader r = new BufferedReader(new InputStreamReader(System.in));
        X = Long.parseLong(r.readLine());
        do{
            i++;
            k = Math.ceil((double)(n/100));
            n += (long)k;
        }while(n<X);
        System.out.println(i);
    } main {
        long X=0;
        int i=0;
        long n = 100;
        double k = 0;
        BufferedReader r = new BufferedReader(new InputStreamReader(System.in));
        X = Long.parseLong(r.readLine());
        do{
            i++;
            k = Math.ceil((double)(n/100));
            n += (long)k;
        }while(n<X);
        System.out.println(i);
    } long X=0; X 0 int i=0; i 0 long n = 100; n 100 double k = 0; k 0 BufferedReader r = new BufferedReader(new InputStreamReader(System.in)); r new BufferedReader(new InputStreamReader(System.in)) X = Long.parseLong(r.readLine()) X Long.parseLong(r.readLine()) Long.parseLong Long r.readLine() r.readLine r do{
            i++;
            k = Math.ceil((double)(n/100));
            n += (long)k;
        }while(n<X); n<X n X {
            i++;
            k = Math.ceil((double)(n/100));
            n += (long)k;
        } i++ i k = Math.ceil((double)(n/100)) k Math.ceil((double)(n/100)) Math.ceil Math (double)(n/100) n 100 n += (long)k n (long)k 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) throws IOException{
        long X=0;
        int i=0;
        long n = 100;
        double k = 0;
        BufferedReader r = new BufferedReader(new InputStreamReader(System.in));
        X = Long.parseLong(r.readLine());
        do{
            i++;
            k = Math.ceil((double)(n/100));
            n += (long)k;
        }while(n<X);
        System.out.println(i);
    }
} public class Main {
    public static void main(String[] args) throws IOException{
        long X=0;
        int i=0;
        long n = 100;
        double k = 0;
        BufferedReader r = new BufferedReader(new InputStreamReader(System.in));
        X = Long.parseLong(r.readLine());
        do{
            i++;
            k = Math.ceil((double)(n/100));
            n += (long)k;
        }while(n<X);
        System.out.println(i);
    }
} Main
import java.io.*;
public class Main {
    public static void main(String[] args) throws IOException{
        long X=0;
        int i=0;
        long n = 100;
        double k = 0;
        BufferedReader r = new BufferedReader(new InputStreamReader(System.in));
        X = Long.parseLong(r.readLine());
        do{
            i++;
            k = Math.ceil((double)(n/100));
            n += (long)k;
        }while(n<X);
        System.out.println(i);
    }
}