def shortPalindrome(s):
  arr1 = [0]*26
  arr2 = [[0]*26 for i in range(26)]
  arr3 = [0]*26
  ans = 0
  for i in range(len(s)):
      idx = ord(s[i]) - ord('a')
      ans += arr3[idx]
      for j in range(26):
          arr3[j] += arr2[j][idx]
      for j in range(26):
          arr2[j][idx] += arr1[j]
      arr1[idx] += 1
  return ans % (10**9+7)