	public class Main {
		 
		public static void main(String[] args) {
	 
			java.util.Scanner scan = new java.util.Scanner(System.in);
		
		
			long x = scan.nextLong();
			long m = 100;
			
			for(int i = 1 ; m < x; i++) {
				m = m / 100 + m ;
				if (m >= x) {
					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