def longestPalindromeSubseq(s):
    size = len(s)
    L = [[0 for x in range(size)] for x in range(size)]

    for i in range(size):
        L[i][i] = 1

    for length in range(2, size + 1):
        for i in range(size - length + 1):
            j = i + length - 1
            if s[i] == s[j] and length == 2:
                L[i][j] = 2
            elif s[i] == s[j]:
                L[i][j] = 2 + L[i + 1][j - 1]
            else:
                L[i][j] = max(L[i][j - 1], L[i + 1][j])

    return L[0][size - 1]

str="babbb"
print(longestPalindromeSubseq(str))