import java.util.Scanner;
public class Main {
    public static void main(String[] args) throws Exception {
        Scanner stdIn= new Scanner(System.in);
        long x = stdIn.nextLong();
        long a=100;
        int y=0;
        for(;a<x;y++){
            a+=a/100;
        }
        System.out.println(y);
    }
} import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args) throws Exception {
        Scanner stdIn= new Scanner(System.in);
        long x = stdIn.nextLong();
        long a=100;
        int y=0;
        for(;a<x;y++){
            a+=a/100;
        }
        System.out.println(y);
    }
} Main public static void main(String[] args) throws Exception {
        Scanner stdIn= new Scanner(System.in);
        long x = stdIn.nextLong();
        long a=100;
        int y=0;
        for(;a<x;y++){
            a+=a/100;
        }
        System.out.println(y);
    } main {
        Scanner stdIn= new Scanner(System.in);
        long x = stdIn.nextLong();
        long a=100;
        int y=0;
        for(;a<x;y++){
            a+=a/100;
        }
        System.out.println(y);
    } Scanner stdIn= new Scanner(System.in); stdIn new Scanner(System.in) long x = stdIn.nextLong(); x stdIn.nextLong() stdIn.nextLong stdIn long a=100; a 100 int y=0; y 0 for(;a<x;y++){
            a+=a/100;
        } ; a<x a x y++ y++ y {
            a+=a/100;
        } {
            a+=a/100;
        } a+=a/100 a a/100 a 100 System.out.println(y) System.out.println System.out System System.out y String[] args args public class Main {
    public static void main(String[] args) throws Exception {
        Scanner stdIn= new Scanner(System.in);
        long x = stdIn.nextLong();
        long a=100;
        int y=0;
        for(;a<x;y++){
            a+=a/100;
        }
        System.out.println(y);
    }
} public class Main {
    public static void main(String[] args) throws Exception {
        Scanner stdIn= new Scanner(System.in);
        long x = stdIn.nextLong();
        long a=100;
        int y=0;
        for(;a<x;y++){
            a+=a/100;
        }
        System.out.println(y);
    }
} Main
import java.util.Scanner;
public class Main {
    public static void main(String[] args) throws Exception {
        Scanner stdIn= new Scanner(System.in);
        long x = stdIn.nextLong();
        long a=100;
        int y=0;
        for(;a<x;y++){
            a+=a/100;
        }
        System.out.println(y);
    }
}
