import java.util.Scanner;
public class Main {
	public static void main(String args[]) {
		Scanner scan=new Scanner(System.in);
		long x=scan.nextLong();
		long m=100;
		long y=1;
		for(;;) {
			m=m+m/100;//m=m*101/100だとオーバーフローする可能性
			if(m>=x) {
				System.out.println(y);
				break;
			}
			else {
				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