import java.util.*;

public class Main{
    void solve(){
        Scanner scan = new Scanner(System.in);
        long x = scan.nextLong();
        long b = 100;
        int out = 0;
        while(b < x){
            b += b / 100;
            out++;
        }
        System.out.println(out);
    }

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

    public static void main(String[] args){
        new Main().solve();
    }
} Main void solve(){
        Scanner scan = new Scanner(System.in);
        long x = scan.nextLong();
        long b = 100;
        int out = 0;
        while(b < x){
            b += b / 100;
            out++;
        }
        System.out.println(out);
    } solve {
        Scanner scan = new Scanner(System.in);
        long x = scan.nextLong();
        long b = 100;
        int out = 0;
        while(b < x){
            b += b / 100;
            out++;
        }
        System.out.println(out);
    } Scanner scan = new Scanner(System.in); scan new Scanner(System.in) long x = scan.nextLong(); x scan.nextLong() scan.nextLong scan long b = 100; b 100 int out = 0; out 0 while(b < x){
            b += b / 100;
            out++;
        } b < x b x {
            b += b / 100;
            out++;
        } b += b / 100 b b / 100 b 100 out++ out System.out.println(out) System.out.println System.out System System.out out public static void main(String[] args){
        new Main().solve();
    } main {
        new Main().solve();
    } new Main().solve() new Main().solve new Main() String[] args args public class Main{
    void solve(){
        Scanner scan = new Scanner(System.in);
        long x = scan.nextLong();
        long b = 100;
        int out = 0;
        while(b < x){
            b += b / 100;
            out++;
        }
        System.out.println(out);
    }

    public static void main(String[] args){
        new Main().solve();
    }
} public class Main{
    void solve(){
        Scanner scan = new Scanner(System.in);
        long x = scan.nextLong();
        long b = 100;
        int out = 0;
        while(b < x){
            b += b / 100;
            out++;
        }
        System.out.println(out);
    }

    public static void main(String[] args){
        new Main().solve();
    }
} Main
import java.util.*;

public class Main{
    void solve(){
        Scanner scan = new Scanner(System.in);
        long x = scan.nextLong();
        long b = 100;
        int out = 0;
        while(b < x){
            b += b / 100;
            out++;
        }
        System.out.println(out);
    }

    public static void main(String[] args){
        new Main().solve();
    }
}
