import java.util.*;
 import java.math.BigInteger;
public class Main
{
	public static  void main(String args[])
	{
		Scanner sc=new Scanner(System.in);
		// String h[]=sc.nextLine().split(" ");
		long n=Long.parseLong(sc.nextLine());
		long a=100;
		int k=0;
		while(a<n)
		{
			a=(long)((double)a*1.01);
			k+=1;
		}
		System.out.println(k);
	}

}



	 import java.util.*; util.* java import java.math.BigInteger; BigInteger java.math public class Main
{
	public static  void main(String args[])
	{
		Scanner sc=new Scanner(System.in);
		// String h[]=sc.nextLine().split(" ");
		long n=Long.parseLong(sc.nextLine());
		long a=100;
		int k=0;
		while(a<n)
		{
			a=(long)((double)a*1.01);
			k+=1;
		}
		System.out.println(k);
	}

} Main public static  void main(String args[])
	{
		Scanner sc=new Scanner(System.in);
		// String h[]=sc.nextLine().split(" ");
		long n=Long.parseLong(sc.nextLine());
		long a=100;
		int k=0;
		while(a<n)
		{
			a=(long)((double)a*1.01);
			k+=1;
		}
		System.out.println(k);
	} main {
		Scanner sc=new Scanner(System.in);
		// String h[]=sc.nextLine().split(" ");
		long n=Long.parseLong(sc.nextLine());
		long a=100;
		int k=0;
		while(a<n)
		{
			a=(long)((double)a*1.01);
			k+=1;
		}
		System.out.println(k);
	} Scanner sc=new Scanner(System.in); sc new Scanner(System.in) long n=Long.parseLong(sc.nextLine()); n Long.parseLong(sc.nextLine()) Long.parseLong Long sc.nextLine() sc.nextLine sc long a=100; a 100 int k=0; k 0 while(a<n)
		{
			a=(long)((double)a*1.01);
			k+=1;
		} a<n a n {
			a=(long)((double)a*1.01);
			k+=1;
		} a=(long)((double)a*1.01) a (long)((double)a*1.01) (double)a 1.01 k+=1 k 1 System.out.println(k) System.out.println System.out System System.out k String args[] args public class Main
{
	public static  void main(String args[])
	{
		Scanner sc=new Scanner(System.in);
		// String h[]=sc.nextLine().split(" ");
		long n=Long.parseLong(sc.nextLine());
		long a=100;
		int k=0;
		while(a<n)
		{
			a=(long)((double)a*1.01);
			k+=1;
		}
		System.out.println(k);
	}

} public class Main
{
	public static  void main(String args[])
	{
		Scanner sc=new Scanner(System.in);
		// String h[]=sc.nextLine().split(" ");
		long n=Long.parseLong(sc.nextLine());
		long a=100;
		int k=0;
		while(a<n)
		{
			a=(long)((double)a*1.01);
			k+=1;
		}
		System.out.println(k);
	}

} Main
import java.util.*;
 import java.math.BigInteger;
public class Main
{
	public static  void main(String args[])
	{
		Scanner sc=new Scanner(System.in);
		// String h[]=sc.nextLine().split(" ");
		long n=Long.parseLong(sc.nextLine());
		long a=100;
		int k=0;
		while(a<n)
		{
			a=(long)((double)a*1.01);
			k+=1;
		}
		System.out.println(k);
	}

}



	
