import java.util.Scanner;
public class Main {
	public static void main(String[] args) {
		Scanner s = new Scanner(System.in);
		long  X = s.nextLong();
	    long money =100;
		long Xyear =0;
		while( money < X ) {
			money *= 1.01;
			Xyear++;
		}
		System.out.println(Xyear);
	}

}
/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