S = input()
from collections import defaultdict
d = defaultdict(list)
ans = 0
N = len(S)
for i in range(len(S)):
  d[S[i]].append(i)
import bisect
for i in range(len(S)):
  x = bisect.bisect_left(d[S[i]],i)
  ans += x*(N-(i+1)-(len(d[S[i]])-(x+1)))
print(ans)