import java.util.Scanner;

public class Main {
  public static void main(String[] args ) throws Exception {
    Scanner sc = new Scanner(System.in);
    double N = Double.parseDouble(sc.next());
	long takahashi = 100L;
    int count = 0;

    while(true) {
    	if(takahashi>=N) {
    		System.out.println(count);
    		break;
    	}
    	takahashi =  (long) (takahashi * 1.01);
    	count++;
    }
  }
}
/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