import java.math.BigDecimal;
import java.math.RoundingMode;
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);

		BigDecimal N =new BigDecimal(sc.nextLine());
		BigDecimal money =new BigDecimal(100);
		BigDecimal r = new BigDecimal("100");
		int con = 0;
		while (money.compareTo(N) < 0) {
			money =money.add(money.divide(r, RoundingMode.FLOOR));
			con++;
		}

		System.out.println(con);

	}
}
/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