import java.io.*;

public class Main {
    public static void main (String[] args) throws Exception {
        BufferedReader reader =
            new BufferedReader (new InputStreamReader (System.in));
        long X = Long.parseLong (reader.readLine());
        long cur = 100L;
        int ans = 0;
        while (cur < X) {
            cur += cur / 100;
            ans++;
        }
        System.out.println (ans);
        return;
    }
} import java.io.*; io.* java public class Main {
    public static void main (String[] args) throws Exception {
        BufferedReader reader =
            new BufferedReader (new InputStreamReader (System.in));
        long X = Long.parseLong (reader.readLine());
        long cur = 100L;
        int ans = 0;
        while (cur < X) {
            cur += cur / 100;
            ans++;
        }
        System.out.println (ans);
        return;
    }
} Main public static void main (String[] args) throws Exception {
        BufferedReader reader =
            new BufferedReader (new InputStreamReader (System.in));
        long X = Long.parseLong (reader.readLine());
        long cur = 100L;
        int ans = 0;
        while (cur < X) {
            cur += cur / 100;
            ans++;
        }
        System.out.println (ans);
        return;
    } main {
        BufferedReader reader =
            new BufferedReader (new InputStreamReader (System.in));
        long X = Long.parseLong (reader.readLine());
        long cur = 100L;
        int ans = 0;
        while (cur < X) {
            cur += cur / 100;
            ans++;
        }
        System.out.println (ans);
        return;
    } BufferedReader reader =
            new BufferedReader (new InputStreamReader (System.in)); reader new BufferedReader (new InputStreamReader (System.in)) long X = Long.parseLong (reader.readLine()); X Long.parseLong (reader.readLine()) Long.parseLong Long reader.readLine() reader.readLine reader long cur = 100L; cur 100L int ans = 0; ans 0 while (cur < X) {
            cur += cur / 100;
            ans++;
        } cur < X cur X {
            cur += cur / 100;
            ans++;
        } cur += cur / 100 cur cur / 100 cur 100 ans++ ans System.out.println (ans) System.out.println System.out System System.out ans return; String[] args args public class Main {
    public static void main (String[] args) throws Exception {
        BufferedReader reader =
            new BufferedReader (new InputStreamReader (System.in));
        long X = Long.parseLong (reader.readLine());
        long cur = 100L;
        int ans = 0;
        while (cur < X) {
            cur += cur / 100;
            ans++;
        }
        System.out.println (ans);
        return;
    }
} public class Main {
    public static void main (String[] args) throws Exception {
        BufferedReader reader =
            new BufferedReader (new InputStreamReader (System.in));
        long X = Long.parseLong (reader.readLine());
        long cur = 100L;
        int ans = 0;
        while (cur < X) {
            cur += cur / 100;
            ans++;
        }
        System.out.println (ans);
        return;
    }
} Main
import java.io.*;

public class Main {
    public static void main (String[] args) throws Exception {
        BufferedReader reader =
            new BufferedReader (new InputStreamReader (System.in));
        long X = Long.parseLong (reader.readLine());
        long cur = 100L;
        int ans = 0;
        while (cur < X) {
            cur += cur / 100;
            ans++;
        }
        System.out.println (ans);
        return;
    }
}