s = input()
counter = {}
base = ans = 0
length = len(s)
for i, char in enumerate(s):
    if not char in counter:
        counter[char] = 1
    else:
        counter[char] += 1
        
        if counter[char] > 2:
            ans -= (counter[char] - 1) * (counter[char] - 2) // 2
            ans += (counter[char] - 1) * (length - (i + 1))
        else:
            ans += length - (i + 1)
print(ans)