def longest_palindromic_subsequence(text):
    n = len(text)
    if n == 0:
        return 0
    dp = [[0] * n for _ in range(n)]
    for left in range(n - 1, -1, -1):
        dp[left][left] = 1
        for right in range(left + 1, n):
            if text[left] == text[right]:
                inner = dp[left + 1][right - 1] if right - left > 1 else 0
                dp[left][right] = inner + 2
            else:
                dp[left][right] = max(dp[left + 1][right], dp[left][right - 1])
    return dp[0][-1]