import sys
input = lambda : sys.stdin.readline().rstrip()
sys.setrecursionlimit(max(1000, 10**9))
write = lambda x: sys.stdout.write(x+"\n")


s = input()
n = len(s)
l = [chr(v) for v in range(ord("a"), ord("z")+1)]
d = {c:i for i,c in enumerate(l)}

dp = [[0]*26 for _ in range(n+1)]
nums = [[0]*26 for _ in range(n+1)]
dp[1][d[s[0]]] = 1
nums[1][d[s[0]]] = 1
M = 10**9+7
for i in range(2, n+1):
    for j,c in enumerate(l):
        if s[i-1]==c:
            nums[i][j] = sum(nums[i-1][k] for k in range(26)) + nums[i-1][j] + 1
            dp[i][j] = sum(dp[i-1][k] for k in range(26) if k!=j) + (sum(nums[i-1][k] for k in range(26) if k!=j)) + 2*dp[i-1][j] + 1
        else:
            nums[i][j] = nums[i-1][j]
            dp[i][j] = dp[i-1][j]
        nums[i][j] %= M
        dp[i][j] %= M
ans = sum(dp[n][j] for j in range(26)) % M
print(ans%M)