import java.util.Scanner;
import java.util.Arrays;
import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;

class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    Double X=sc.nextDouble();
    Double N=100.0;
    long S=0;
    while(true){
      if(N>=X){
         break;
      }
        S++;
        N=N*1.01;
        if(!(N%1==0)){
          N=N-N%1;
        }
    }

      System.out.println(S);




  }
} import java.util.Scanner; Scanner java.util import java.util.Arrays; Arrays java.util import java.util.ArrayList; ArrayList java.util import java.util.List; List java.util import java.util.stream.Collectors; Collectors java.util.stream class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    Double X=sc.nextDouble();
    Double N=100.0;
    long S=0;
    while(true){
      if(N>=X){
         break;
      }
        S++;
        N=N*1.01;
        if(!(N%1==0)){
          N=N-N%1;
        }
    }

      System.out.println(S);




  }
} Main public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    Double X=sc.nextDouble();
    Double N=100.0;
    long S=0;
    while(true){
      if(N>=X){
         break;
      }
        S++;
        N=N*1.01;
        if(!(N%1==0)){
          N=N-N%1;
        }
    }

      System.out.println(S);




  } main {
    Scanner sc = new Scanner(System.in);
    Double X=sc.nextDouble();
    Double N=100.0;
    long S=0;
    while(true){
      if(N>=X){
         break;
      }
        S++;
        N=N*1.01;
        if(!(N%1==0)){
          N=N-N%1;
        }
    }

      System.out.println(S);




  } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) Double X=sc.nextDouble(); X sc.nextDouble() sc.nextDouble sc Double N=100.0; N 100.0 long S=0; S 0 while(true){
      if(N>=X){
         break;
      }
        S++;
        N=N*1.01;
        if(!(N%1==0)){
          N=N-N%1;
        }
    } true {
      if(N>=X){
         break;
      }
        S++;
        N=N*1.01;
        if(!(N%1==0)){
          N=N-N%1;
        }
    } if(N>=X){
         break;
      } N>=X N X {
         break;
      } break; S++ S N=N*1.01 N N*1.01 N 1.01 if(!(N%1==0)){
          N=N-N%1;
        } !(N%1==0) (N%1==0) N%1 N 1 0 {
          N=N-N%1;
        } N=N-N%1 N N-N%1 N N%1 N 1 System.out.println(S) System.out.println System.out System System.out S String[] args args
import java.util.Scanner;
import java.util.Arrays;
import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;

class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    Double X=sc.nextDouble();
    Double N=100.0;
    long S=0;
    while(true){
      if(N>=X){
         break;
      }
        S++;
        N=N*1.01;
        if(!(N%1==0)){
          N=N-N%1;
        }
    }

      System.out.println(S);




  }
}
