import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
 
class Main {
    public static void main(final String[] args) throws Exception {
 
        try (BufferedReader br = new BufferedReader(new InputStreamReader(System.in));) {
            long N = Long.parseLong(br.readLine());
            long ans = 0;
            long base = 100;
            while (base < N) {
                base = base + (base * 1 / 100);
                ans++;
            }
 
            System.out.println(ans);
        } catch (IOException | NumberFormatException e) {
            e.printStackTrace();
            System.exit(0);
        } catch (final Exception e) {
            e.printStackTrace();
            System.exit(0);
        }
    }
}
/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