import java.util.Scanner;
public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        long x = sc.nextLong();
        long i = 100;
        int k = 0;
        while(i < x){
            i = i + i / 100;
            k++;
        }
        System.out.println(k);
        sc.close();
    }
} import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        long x = sc.nextLong();
        long i = 100;
        int k = 0;
        while(i < x){
            i = i + i / 100;
            k++;
        }
        System.out.println(k);
        sc.close();
    }
} Main public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        long x = sc.nextLong();
        long i = 100;
        int k = 0;
        while(i < x){
            i = i + i / 100;
            k++;
        }
        System.out.println(k);
        sc.close();
    } main {
        Scanner sc = new Scanner(System.in);
        long x = sc.nextLong();
        long i = 100;
        int k = 0;
        while(i < x){
            i = i + i / 100;
            k++;
        }
        System.out.println(k);
        sc.close();
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) long x = sc.nextLong(); x sc.nextLong() sc.nextLong sc long i = 100; i 100 int k = 0; k 0 while(i < x){
            i = i + i / 100;
            k++;
        } i < x i x {
            i = i + i / 100;
            k++;
        } i = i + i / 100 i i + i / 100 i i / 100 i 100 k++ k System.out.println(k) System.out.println System.out System System.out k sc.close() sc.close sc String[] args args public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        long x = sc.nextLong();
        long i = 100;
        int k = 0;
        while(i < x){
            i = i + i / 100;
            k++;
        }
        System.out.println(k);
        sc.close();
    }
} public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        long x = sc.nextLong();
        long i = 100;
        int k = 0;
        while(i < x){
            i = i + i / 100;
            k++;
        }
        System.out.println(k);
        sc.close();
    }
} Main
import java.util.Scanner;
public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        long x = sc.nextLong();
        long i = 100;
        int k = 0;
        while(i < x){
            i = i + i / 100;
            k++;
        }
        System.out.println(k);
        sc.close();
    }
}