最长回文子串

def solve(____):
    s = str(____).strip()
    n = len(____)
    best = ____
    for i in range(____):
        for odd in [True, False]:
            l, r = i, i if odd else i+____
            while l >= ____ and r < n and s[l] == s[r]:
                best = max(____)
                l -= ____; r += ____
    print(____)