CF1879D Sum of XOR Functions

You are given an array $ a $ of length $ n $ consisting of non-negative integers. You have to calculate the value of $ \sum_{l=1}^{n} \sum_{r=l}^{n} f(l, r) \cdot (r - l + 1) $ , where $ f(l, r) $ is $ a_l \oplus a_{l+1} \oplus \dots \oplus a_{r-1} \oplus a_r $ (the character $ \oplus $ denotes bitwise XOR). Since the answer can be very large, print it modulo $ 998244353 $ .

N/A

N/A

In the first example, the answer is equal to $ f(1, 1) + 2 \cdot f(1, 2) + 3 \cdot f(1, 3) + f(2, 2) + 2 \cdot f(2, 3) + f(3, 3) = $ $ = 1 + 2 \cdot 2 + 3 \cdot 0 + 3 + 2 \cdot 1 + 2 = 12 $ .