import sys
def input():
    return sys.stdin.readline().rstrip()

def main():
    S = [ord(s)-65 for s in list(input())]
    ct = [0]*26
    ans = 0
    for s in S:
        ct[s] += 1
        for i in range(26):
            if i == s:
                continue
            ans += ct[i]*(ct[i]-1)//2
    print(ans)
if __name__ == "__main__":
    main()