public static String getOverallScore(String input) {
        Stack<Character> stack = new Stack<>();

        for (char symbol : input.toCharArray()) {
            while (!stack.isEmpty() && hasHigherPrecedence(symbol, stack.peek())) {
                stack.pop();
            }
            stack.push(symbol);
        }

        StringBuilder result = new StringBuilder();
        for (char symbol : stack) {
            result.append(symbol);
        }
        return result.toString();
    }

    private static boolean hasHigherPrecedence(char newSymbol, char existingSymbol) {
        String precedence = "ABCDEF";
        return precedence.indexOf(newSymbol) < precedence.indexOf(existingSymbol);
    }

static final int MOD = 1000000007;
public static long calculateSurprisingSum(long N) {
        long sum = 0;
        
        for(int i = 0; i <= 33; i++) {
            for(int j = i + 1; j <= 33; j++) {
                for(int k = j + 1; k <= 33; k++) {
                    long number = (1L << i) + (1L << j) + (1L << k);
                    if(number <= N) {
                        sum = (sum + number) % MOD;
                    }
                }
            }
        }
        
        return sum;
    }