S = input() L = len(S) MOD = 1_000_000_007 rev = lambda x: L - 1 - x st = set() for i in range(L // 2): # 奇数長 j = 0 while i - j >= 0 and i + j < L // 2: if S[i - j] == S[rev(i + j)] and S[i + j] == S[rev(i - j)]: st.add((i - j, i + j)) j += 1 else: break # 偶数長 j = 0 while i - j >= 0 and i + j + 1 < L // 2: if S[i - j] == S[rev(i + j + 1)] and S[i + j + 1] == S[rev(i - j)]: st.add((i - j, i + j + 1)) j += 1 else: break dp = [0] * (L // 2 + 1) dp[0] = 1 for i in range(L // 2): for j in range(i, L // 2): if (i, j) in st: dp[j + 1] = (dp[j + 1] + dp[i]) % MOD print(sum(dp) % MOD)