8084번 - The Number of Symmetrical Choices 다국어

문제

We are given two sequences of words: (x₁, ..., x_n) and (y₁, ..., y_n), with 1 ≤ n ≤ 30. For every i, 1 ≤ i ≤ n, we chose one of the two words: x_i or y_i. The chosen words are merged in order of increasing indices. The choice consists of n steps. In each step we decide to take the i-th word from the first or from the second sequence of words. More formally: the choice is a sequence of length n whose elements are numbers 1 and 2. It is possible that different choices lead to the same word. We say that a choice is symmetrical if its result is a palindrome, i.e. a word that is identical when we read it from left to right and from right to left.

Write a program that:

• reads from the standard input: the number n and two sequences of words (x₁, ..., x_n) and (y₁, ..., y_n),
• computes the number of symmetrical choices for the given sequences,
• writes the result to the standard output.

입력

In the first line of the standard input there is one positive integer n ≤ 30. In the following n lines there are written consecutive words of the sequence (x_i) — one word in one line. In the following n lines there are written (in the similar way) consecutive words of the sequence (y_i). Each word consists solely of small letters of the English alphabet (from a to z). The total length of all words is from the range [1..400].

출력

In the standard output there should be written one non-negative integer — the number of symmetrical choices.

제한

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