import java.util.Scanner;
public class Main {
	public static void main(String[] args) {
		int year;
		long money;
		double X;
		Scanner sc = new Scanner(System.in);
		
		X = Double.parseDouble(sc.next());
		sc.close();
		
		money = 100;
		for(year = 0;money < X;year++,money *= 1.01);
		
		System.out.println(year);
	}
}

/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