import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner a = new Scanner(System.in);		
		long money = a.nextLong();
		long b = 100;
		int num = 0;
		for(long i = b; i <= money; i++) {
			long risi = b / 100;
			b = b + risi;
			i = b;
			num++;

		}
		System.out.println(num);
		
	}
}
/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