import java.util.*;

public class Main {
    public static void main(String[] args ) throws Exception {
        Scanner sc = new Scanner(System.in);
        long X = sc.nextLong();
        long start = 100;
        long interest = 0;
        long count = 0;
        while(true){
          	interest = 0;
          	count++;
            interest += (start/100);
            start += interest;
            if(X <= start){
                System.out.println(count);
              	break;
            }
        }
    }
} import java.util.*; util.* java public class Main {
    public static void main(String[] args ) throws Exception {
        Scanner sc = new Scanner(System.in);
        long X = sc.nextLong();
        long start = 100;
        long interest = 0;
        long count = 0;
        while(true){
          	interest = 0;
          	count++;
            interest += (start/100);
            start += interest;
            if(X <= start){
                System.out.println(count);
              	break;
            }
        }
    }
} Main public static void main(String[] args ) throws Exception {
        Scanner sc = new Scanner(System.in);
        long X = sc.nextLong();
        long start = 100;
        long interest = 0;
        long count = 0;
        while(true){
          	interest = 0;
          	count++;
            interest += (start/100);
            start += interest;
            if(X <= start){
                System.out.println(count);
              	break;
            }
        }
    } main {
        Scanner sc = new Scanner(System.in);
        long X = sc.nextLong();
        long start = 100;
        long interest = 0;
        long count = 0;
        while(true){
          	interest = 0;
          	count++;
            interest += (start/100);
            start += interest;
            if(X <= start){
                System.out.println(count);
              	break;
            }
        }
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) long X = sc.nextLong(); X sc.nextLong() sc.nextLong sc long start = 100; start 100 long interest = 0; interest 0 long count = 0; count 0 while(true){
          	interest = 0;
          	count++;
            interest += (start/100);
            start += interest;
            if(X <= start){
                System.out.println(count);
              	break;
            }
        } true {
          	interest = 0;
          	count++;
            interest += (start/100);
            start += interest;
            if(X <= start){
                System.out.println(count);
              	break;
            }
        } interest = 0 interest 0 count++ count interest += (start/100) interest (start/100) start 100 start += interest start interest if(X <= start){
                System.out.println(count);
              	break;
            } X <= start X start {
                System.out.println(count);
              	break;
            } System.out.println(count) System.out.println System.out System System.out count break; String[] args args public class Main {
    public static void main(String[] args ) throws Exception {
        Scanner sc = new Scanner(System.in);
        long X = sc.nextLong();
        long start = 100;
        long interest = 0;
        long count = 0;
        while(true){
          	interest = 0;
          	count++;
            interest += (start/100);
            start += interest;
            if(X <= start){
                System.out.println(count);
              	break;
            }
        }
    }
} public class Main {
    public static void main(String[] args ) throws Exception {
        Scanner sc = new Scanner(System.in);
        long X = sc.nextLong();
        long start = 100;
        long interest = 0;
        long count = 0;
        while(true){
          	interest = 0;
          	count++;
            interest += (start/100);
            start += interest;
            if(X <= start){
                System.out.println(count);
              	break;
            }
        }
    }
} Main
import java.util.*;

public class Main {
    public static void main(String[] args ) throws Exception {
        Scanner sc = new Scanner(System.in);
        long X = sc.nextLong();
        long start = 100;
        long interest = 0;
        long count = 0;
        while(true){
          	interest = 0;
          	count++;
            interest += (start/100);
            start += interest;
            if(X <= start){
                System.out.println(count);
              	break;
            }
        }
    }
}
