import java.util.regex.Pattern;

public class Main {
	public static void main(String[] args) {
		String str = "snake_case_to_camel_case";

		str = Pattern.compile("_([a-z])")
					.matcher(str)
					.replaceAll(m -> m.group(1).toUpperCase());

		System.out.println(str);
	}
}