import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Scanner;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TaskB solver = new TaskB();
        solver.solve(1, in, out);
        out.close();
    }

    static class TaskB {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            long x = in.nextLong();
            long years = 0;

            out.println(answer(x, 0, 100l));


        }

        public long answer(long x, long years, long current) {

//        double y = ceil(x*1.0000/100.0000);
//        double lgy = Math.log(y);
//        double xx = Math.log(1.0100);
//        double an =  lgy/xx;
//        return (long)ceil(an);
            double cd = current * 1.00000;
            long y = 0;
            while (x > cd) {
                cd = Math.floor(cd * 1.01);
                y++;
            }
            return y;
        }

    }
}
 import java.io.OutputStream; OutputStream java.io import java.io.IOException; IOException java.io import java.io.InputStream; InputStream java.io import java.io.PrintWriter; PrintWriter java.io import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TaskB solver = new TaskB();
        solver.solve(1, in, out);
        out.close();
    }

    static class TaskB {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            long x = in.nextLong();
            long years = 0;

            out.println(answer(x, 0, 100l));


        }

        public long answer(long x, long years, long current) {

//        double y = ceil(x*1.0000/100.0000);
//        double lgy = Math.log(y);
//        double xx = Math.log(1.0100);
//        double an =  lgy/xx;
//        return (long)ceil(an);
            double cd = current * 1.00000;
            long y = 0;
            while (x > cd) {
                cd = Math.floor(cd * 1.01);
                y++;
            }
            return y;
        }

    }
} Main public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TaskB solver = new TaskB();
        solver.solve(1, in, out);
        out.close();
    } main {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TaskB solver = new TaskB();
        solver.solve(1, in, out);
        out.close();
    } InputStream inputStream = System.in; inputStream System.in System System.in OutputStream outputStream = System.out; outputStream System.out System System.out Scanner in = new Scanner(inputStream); in new Scanner(inputStream) PrintWriter out = new PrintWriter(outputStream); out new PrintWriter(outputStream) TaskB solver = new TaskB(); solver new TaskB() solver.solve(1, in, out) solver.solve solver 1 in out out.close() out.close out String[] args args static class TaskB {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            long x = in.nextLong();
            long years = 0;

            out.println(answer(x, 0, 100l));


        }

        public long answer(long x, long years, long current) {

//        double y = ceil(x*1.0000/100.0000);
//        double lgy = Math.log(y);
//        double xx = Math.log(1.0100);
//        double an =  lgy/xx;
//        return (long)ceil(an);
            double cd = current * 1.00000;
            long y = 0;
            while (x > cd) {
                cd = Math.floor(cd * 1.01);
                y++;
            }
            return y;
        }

    } TaskB public void solve(int testNumber, Scanner in, PrintWriter out) {
            long x = in.nextLong();
            long years = 0;

            out.println(answer(x, 0, 100l));


        } solve {
            long x = in.nextLong();
            long years = 0;

            out.println(answer(x, 0, 100l));


        } long x = in.nextLong(); x in.nextLong() in.nextLong in long years = 0; years 0 out.println(answer(x, 0, 100l)) out.println out answer(x, 0, 100l) answer x 0 100l int testNumber testNumber Scanner in in PrintWriter out out public long answer(long x, long years, long current) {

//        double y = ceil(x*1.0000/100.0000);
//        double lgy = Math.log(y);
//        double xx = Math.log(1.0100);
//        double an =  lgy/xx;
//        return (long)ceil(an);
            double cd = current * 1.00000;
            long y = 0;
            while (x > cd) {
                cd = Math.floor(cd * 1.01);
                y++;
            }
            return y;
        } answer {

//        double y = ceil(x*1.0000/100.0000);
//        double lgy = Math.log(y);
//        double xx = Math.log(1.0100);
//        double an =  lgy/xx;
//        return (long)ceil(an);
            double cd = current * 1.00000;
            long y = 0;
            while (x > cd) {
                cd = Math.floor(cd * 1.01);
                y++;
            }
            return y;
        } double cd = current * 1.00000; cd current * 1.00000 current 1.00000 long y = 0; y 0 while (x > cd) {
                cd = Math.floor(cd * 1.01);
                y++;
            } x > cd x cd {
                cd = Math.floor(cd * 1.01);
                y++;
            } cd = Math.floor(cd * 1.01) cd Math.floor(cd * 1.01) Math.floor Math cd * 1.01 cd 1.01 y++ y return y; y long x x long years years long current current public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TaskB solver = new TaskB();
        solver.solve(1, in, out);
        out.close();
    }

    static class TaskB {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            long x = in.nextLong();
            long years = 0;

            out.println(answer(x, 0, 100l));


        }

        public long answer(long x, long years, long current) {

//        double y = ceil(x*1.0000/100.0000);
//        double lgy = Math.log(y);
//        double xx = Math.log(1.0100);
//        double an =  lgy/xx;
//        return (long)ceil(an);
            double cd = current * 1.00000;
            long y = 0;
            while (x > cd) {
                cd = Math.floor(cd * 1.01);
                y++;
            }
            return y;
        }

    }
} public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TaskB solver = new TaskB();
        solver.solve(1, in, out);
        out.close();
    }

    static class TaskB {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            long x = in.nextLong();
            long years = 0;

            out.println(answer(x, 0, 100l));


        }

        public long answer(long x, long years, long current) {

//        double y = ceil(x*1.0000/100.0000);
//        double lgy = Math.log(y);
//        double xx = Math.log(1.0100);
//        double an =  lgy/xx;
//        return (long)ceil(an);
            double cd = current * 1.00000;
            long y = 0;
            while (x > cd) {
                cd = Math.floor(cd * 1.01);
                y++;
            }
            return y;
        }

    }
} Main
import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.Scanner;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        Scanner in = new Scanner(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        TaskB solver = new TaskB();
        solver.solve(1, in, out);
        out.close();
    }

    static class TaskB {
        public void solve(int testNumber, Scanner in, PrintWriter out) {
            long x = in.nextLong();
            long years = 0;

            out.println(answer(x, 0, 100l));


        }

        public long answer(long x, long years, long current) {

//        double y = ceil(x*1.0000/100.0000);
//        double lgy = Math.log(y);
//        double xx = Math.log(1.0100);
//        double an =  lgy/xx;
//        return (long)ceil(an);
            double cd = current * 1.00000;
            long y = 0;
            while (x > cd) {
                cd = Math.floor(cd * 1.01);
                y++;
            }
            return y;
        }

    }
}

