import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        long N = sc.nextLong();
        long ans = 100;
        long sum = 0;
        while(ans<N)
        {
            ans = ans + (long)(ans /100);
            sum++;
        }
        System.out.println(sum);
    }
} import java.util.*; util.* java public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        long N = sc.nextLong();
        long ans = 100;
        long sum = 0;
        while(ans<N)
        {
            ans = ans + (long)(ans /100);
            sum++;
        }
        System.out.println(sum);
    }
} Main public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        long N = sc.nextLong();
        long ans = 100;
        long sum = 0;
        while(ans<N)
        {
            ans = ans + (long)(ans /100);
            sum++;
        }
        System.out.println(sum);
    } main {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        long N = sc.nextLong();
        long ans = 100;
        long sum = 0;
        while(ans<N)
        {
            ans = ans + (long)(ans /100);
            sum++;
        }
        System.out.println(sum);
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) long N = sc.nextLong(); N sc.nextLong() sc.nextLong sc long ans = 100; ans 100 long sum = 0; sum 0 while(ans<N)
        {
            ans = ans + (long)(ans /100);
            sum++;
        } ans<N ans N {
            ans = ans + (long)(ans /100);
            sum++;
        } ans = ans + (long)(ans /100) ans ans + (long)(ans /100) ans (long)(ans /100) ans 100 sum++ sum System.out.println(sum) System.out.println System.out System System.out sum String[] args args public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        long N = sc.nextLong();
        long ans = 100;
        long sum = 0;
        while(ans<N)
        {
            ans = ans + (long)(ans /100);
            sum++;
        }
        System.out.println(sum);
    }
} public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        long N = sc.nextLong();
        long ans = 100;
        long sum = 0;
        while(ans<N)
        {
            ans = ans + (long)(ans /100);
            sum++;
        }
        System.out.println(sum);
    }
} Main
import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        // Your code here!
        Scanner sc = new Scanner(System.in);
        long N = sc.nextLong();
        long ans = 100;
        long sum = 0;
        while(ans<N)
        {
            ans = ans + (long)(ans /100);
            sum++;
        }
        System.out.println(sum);
    }
}
