#yukicoder practice

#runs in subsequences

mod = 10**9 + 7

alpha_list = list("abcdefghijklmnopqrstuvwxyz")

num_dict = {alpha_list[i]: i for i, v in enumerate(alpha_list)}


def to_num(string):
    return num_dict[string]


def main():
    s = list(input())
    N = len(s)

    dp = [[[0, 0] for j in range(26)] for i in range(N)]
    sumdp = [[0, 0] for i in range(N)]
    #dp[index][alpha] = [sum_of_len,group_count]
    a = list(map(to_num, s))

    dp[0][a[0]] = [1, 1]
    sumdp[0] = [1, 1]
    for i in range(1, N):
        num = a[i]
        sum_len, group_cnt = sumdp[i-1]
        for j in range(26):
            if j != num:
                dp[i][j][0] = dp[i-1][j][0]
                dp[i][j][1] = dp[i-1][j][1]

            else:
                dp[i][j][0] = (sum_len + dp[i-1][j][0] + 1 +
                               group_cnt - dp[i-1][j][1]) % mod
                dp[i][j][1] = (group_cnt + dp[i-1][j][1] + 1) % mod

            sumdp[i][0] += dp[i][j][0]
            sumdp[i][1] += dp[i][j][1]
            sumdp[i][0] %= mod
            sumdp[i][1] %= mod

    ans = sumdp[N-1][0]
    print(ans % mod)
    return


if __name__ == "__main__":
    main()