import java.util.Scanner;
public class Main {
 
	public static void main(String[] args) {
		Scanner stdIn =new Scanner(System.in);
		long X =stdIn.nextLong();
		long Y=100;
		long i;
		
		for(i=0;Y<X;i++) {
			Y=(long) (Y*1.01);
			Y=Y/1;
		}
		System.out.println(i);
		
		
	}
 
}
/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