import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        long n=in.nextLong();
        int num=0;
        for(long i=100;i<n;){
            i+=i/100;
            num++;

            if(i>=n){
                System.out.println(num);
                return;
            }

        }
    }
} import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        long n=in.nextLong();
        int num=0;
        for(long i=100;i<n;){
            i+=i/100;
            num++;

            if(i>=n){
                System.out.println(num);
                return;
            }

        }
    }
} Main public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        long n=in.nextLong();
        int num=0;
        for(long i=100;i<n;){
            i+=i/100;
            num++;

            if(i>=n){
                System.out.println(num);
                return;
            }

        }
    } main {
        Scanner in = new Scanner(System.in);
        long n=in.nextLong();
        int num=0;
        for(long i=100;i<n;){
            i+=i/100;
            num++;

            if(i>=n){
                System.out.println(num);
                return;
            }

        }
    } Scanner in = new Scanner(System.in); in new Scanner(System.in) long n=in.nextLong(); n in.nextLong() in.nextLong in int num=0; num 0 for(long i=100;i<n;){
            i+=i/100;
            num++;

            if(i>=n){
                System.out.println(num);
                return;
            }

        } long i=100; long i=100; i 100 i<n i n {
            i+=i/100;
            num++;

            if(i>=n){
                System.out.println(num);
                return;
            }

        } {
            i+=i/100;
            num++;

            if(i>=n){
                System.out.println(num);
                return;
            }

        } i+=i/100 i i/100 i 100 num++ num if(i>=n){
                System.out.println(num);
                return;
            } i>=n i n {
                System.out.println(num);
                return;
            } System.out.println(num) System.out.println System.out System System.out num return; String[] args args public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        long n=in.nextLong();
        int num=0;
        for(long i=100;i<n;){
            i+=i/100;
            num++;

            if(i>=n){
                System.out.println(num);
                return;
            }

        }
    }
} public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        long n=in.nextLong();
        int num=0;
        for(long i=100;i<n;){
            i+=i/100;
            num++;

            if(i>=n){
                System.out.println(num);
                return;
            }

        }
    }
} Main
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        long n=in.nextLong();
        int num=0;
        for(long i=100;i<n;){
            i+=i/100;
            num++;

            if(i>=n){
                System.out.println(num);
                return;
            }

        }
    }
}
