import java.util.*;

public class Main {

	public static void main(String[] args) {
	
		Scanner sc = new Scanner(System.in);
		long x = sc.nextLong();
		long m = 100L;
		long y = 0L;
		while (m < x) {
			y++;
			m = m + m / 100;
		}
		System.out.println(y);
	}
}
/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