import java.util.*;
class Main {
    public static void main(String[] args){
        Scanner scan = new Scanner(System.in);
        long x = scan.nextLong();
        long y = 100;
        int year = 0;
        outloop:for(int i = 1; ;i++){
            y = y + (y/100);
            if (y>=x){
                year = i;
                break outloop;
            }
        }
        System.out.println(year);
        }
        } import java.util.*; util.* java class Main {
    public static void main(String[] args){
        Scanner scan = new Scanner(System.in);
        long x = scan.nextLong();
        long y = 100;
        int year = 0;
        outloop:for(int i = 1; ;i++){
            y = y + (y/100);
            if (y>=x){
                year = i;
                break outloop;
            }
        }
        System.out.println(year);
        }
        } Main public static void main(String[] args){
        Scanner scan = new Scanner(System.in);
        long x = scan.nextLong();
        long y = 100;
        int year = 0;
        outloop:for(int i = 1; ;i++){
            y = y + (y/100);
            if (y>=x){
                year = i;
                break outloop;
            }
        }
        System.out.println(year);
        } main {
        Scanner scan = new Scanner(System.in);
        long x = scan.nextLong();
        long y = 100;
        int year = 0;
        outloop:for(int i = 1; ;i++){
            y = y + (y/100);
            if (y>=x){
                year = i;
                break outloop;
            }
        }
        System.out.println(year);
        } Scanner scan = new Scanner(System.in); scan new Scanner(System.in) long x = scan.nextLong(); x scan.nextLong() scan.nextLong scan long y = 100; y 100 int year = 0; year 0 System.out.println(year) System.out.println System.out System System.out year String[] args args
import java.util.*;
class Main {
    public static void main(String[] args){
        Scanner scan = new Scanner(System.in);
        long x = scan.nextLong();
        long y = 100;
        int year = 0;
        outloop:for(int i = 1; ;i++){
            y = y + (y/100);
            if (y>=x){
                year = i;
                break outloop;
            }
        }
        System.out.println(year);
        }
        }