import java.util.*;
public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		String x = sc.next();
        long X = Long.parseLong(x);
        long sum = 100;
        for(int i = 1; i <= 4000; i++){
          sum = sum + (long)(sum * 0.01);
          if(sum >= X){
            System.out.println(i);
            break;
          }
        }  
    }
}
/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