import java.util.Scanner;

public class Main {
	static long X;
	static int m=0;
	static long a=100;
	static boolean n=true;
	public static void main(String[]args) {
		Scanner sc=new Scanner(System.in);
		X=sc.nextLong();
		while(X>a) {
			m=m+1;
			a=a/100+a;
		}
		System.out.println(m);
	}
}

/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