import java.util.*;
public class Main{
  public static void main(String[] args){
    Scanner sc =new Scanner(System.in);
    long x =sc.nextLong();
    long y=100;
    double z;
    for(long i=1;;i++){
      z=y*1.01;
      y=(long)z;
      if(y>=x){System.out.println(i);System.exit(0);}
    }
  }
} import java.util.*; util.* java public class Main{
  public static void main(String[] args){
    Scanner sc =new Scanner(System.in);
    long x =sc.nextLong();
    long y=100;
    double z;
    for(long i=1;;i++){
      z=y*1.01;
      y=(long)z;
      if(y>=x){System.out.println(i);System.exit(0);}
    }
  }
} Main public static void main(String[] args){
    Scanner sc =new Scanner(System.in);
    long x =sc.nextLong();
    long y=100;
    double z;
    for(long i=1;;i++){
      z=y*1.01;
      y=(long)z;
      if(y>=x){System.out.println(i);System.exit(0);}
    }
  } main {
    Scanner sc =new Scanner(System.in);
    long x =sc.nextLong();
    long y=100;
    double z;
    for(long i=1;;i++){
      z=y*1.01;
      y=(long)z;
      if(y>=x){System.out.println(i);System.exit(0);}
    }
  } Scanner sc =new Scanner(System.in); sc new Scanner(System.in) long x =sc.nextLong(); x sc.nextLong() sc.nextLong sc long y=100; y 100 double z; z for(long i=1;;i++){
      z=y*1.01;
      y=(long)z;
      if(y>=x){System.out.println(i);System.exit(0);}
    } long i=1; long i=1; i 1 i++ i++ i {
      z=y*1.01;
      y=(long)z;
      if(y>=x){System.out.println(i);System.exit(0);}
    } {
      z=y*1.01;
      y=(long)z;
      if(y>=x){System.out.println(i);System.exit(0);}
    } z=y*1.01 z y*1.01 y 1.01 y=(long)z y (long)z if(y>=x){System.out.println(i);System.exit(0);} y>=x y x {System.out.println(i);System.exit(0);} System.out.println(i) System.out.println System.out System System.out i System.exit(0) System.exit System 0 String[] args args public class Main{
  public static void main(String[] args){
    Scanner sc =new Scanner(System.in);
    long x =sc.nextLong();
    long y=100;
    double z;
    for(long i=1;;i++){
      z=y*1.01;
      y=(long)z;
      if(y>=x){System.out.println(i);System.exit(0);}
    }
  }
} public class Main{
  public static void main(String[] args){
    Scanner sc =new Scanner(System.in);
    long x =sc.nextLong();
    long y=100;
    double z;
    for(long i=1;;i++){
      z=y*1.01;
      y=(long)z;
      if(y>=x){System.out.println(i);System.exit(0);}
    }
  }
} Main
import java.util.*;
public class Main{
  public static void main(String[] args){
    Scanner sc =new Scanner(System.in);
    long x =sc.nextLong();
    long y=100;
    double z;
    for(long i=1;;i++){
      z=y*1.01;
      y=(long)z;
      if(y>=x){System.out.println(i);System.exit(0);}
    }
  }
}