import java.util.*;
class Main{
  public static void main(String args[]){
    Scanner sc = new Scanner(System.in);
    long x = sc.nextLong();
    long n=100;
    int i=1;
    for(i=0;n<x;i++){
      n=(long)(n*1.01);
    }
    pl(i+"");
  }

  public static int aa(int n){
    if(n>0){return 1;}
    return 0;
  }

  public static void pr(String str){
    System.out.print(str);
  }
  public static void pl(String str){
    System.out.println(str);
  }
} import java.util.*; util.* java class Main{
  public static void main(String args[]){
    Scanner sc = new Scanner(System.in);
    long x = sc.nextLong();
    long n=100;
    int i=1;
    for(i=0;n<x;i++){
      n=(long)(n*1.01);
    }
    pl(i+"");
  }

  public static int aa(int n){
    if(n>0){return 1;}
    return 0;
  }

  public static void pr(String str){
    System.out.print(str);
  }
  public static void pl(String str){
    System.out.println(str);
  }
} Main public static void main(String args[]){
    Scanner sc = new Scanner(System.in);
    long x = sc.nextLong();
    long n=100;
    int i=1;
    for(i=0;n<x;i++){
      n=(long)(n*1.01);
    }
    pl(i+"");
  } main {
    Scanner sc = new Scanner(System.in);
    long x = sc.nextLong();
    long n=100;
    int i=1;
    for(i=0;n<x;i++){
      n=(long)(n*1.01);
    }
    pl(i+"");
  } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) long x = sc.nextLong(); x sc.nextLong() sc.nextLong sc long n=100; n 100 int i=1; i 1 for(i=0;n<x;i++){
      n=(long)(n*1.01);
    } i=0; i=0 i 0 n<x n x i++ i++ i {
      n=(long)(n*1.01);
    } {
      n=(long)(n*1.01);
    } n=(long)(n*1.01) n (long)(n*1.01) n 1.01 pl(i+"") pl i+"" i "" String args[] args public static int aa(int n){
    if(n>0){return 1;}
    return 0;
  } aa {
    if(n>0){return 1;}
    return 0;
  } if(n>0){return 1;} n>0 n 0 {return 1;} return 1; 1 return 0; 0 int n n public static void pr(String str){
    System.out.print(str);
  } pr {
    System.out.print(str);
  } System.out.print(str) System.out.print System.out System System.out str String str str public static void pl(String str){
    System.out.println(str);
  } pl {
    System.out.println(str);
  } System.out.println(str) System.out.println System.out System System.out str String str str
import java.util.*;
class Main{
  public static void main(String args[]){
    Scanner sc = new Scanner(System.in);
    long x = sc.nextLong();
    long n=100;
    int i=1;
    for(i=0;n<x;i++){
      n=(long)(n*1.01);
    }
    pl(i+"");
  }

  public static int aa(int n){
    if(n>0){return 1;}
    return 0;
  }

  public static void pr(String str){
    System.out.print(str);
  }
  public static void pl(String str){
    System.out.println(str);
  }
}
