import java.util.*;
import java.io.*;

class Main{
    public static void main(String args[])throws IOException{
        try(BufferedReader br = new BufferedReader(new InputStreamReader(System.in))){
          double X = Double.parseDouble(br.readLine());
          double tmp = 100.0;
          int count = 0;

          do{
            tmp = tmp * 1.01;
            tmp = Math.floor(tmp);
            count++;
          }while(X > tmp);
          
          System.out.println(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