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

public class EscapeSpecialChar{
	public static void main(String[] args) throws IOException{
		BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
		System.out.print("Enter string to find special characters: ");
		String string = in.readLine();
		Pattern pattern = Pattern.compile("[^a-zA-z0-9 ]");
		Matcher matcher = pattern.matcher(string);
		String str = matcher.replaceAll("F");
		System.out.print(str);
	}
}