public String solution(String S, int K) {
        // Days of the week in order
        String[] days = {"Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"};

        // Map days to their indices for quick lookup
        Map<String, Integer> dayIndex = new HashMap<>();
        for (int i = 0; i < days.length; i++) {
            dayIndex.put(days[i], i);
        }

        // Find the current day index
        int currentIndex = dayIndex.get(S);

        // Calculate the new index using modular arithmetic
        int newIndex = (currentIndex + K) % 7;

        // Return the corresponding day
        return days[newIndex];
    }