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);
	}

}



	

/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz