CF50B.Choosing Symbol Pairs

There is a given string S consisting of N symbols. Your task is to find the number of ordered pairs of integers i and j such that

1. 1 ≤ i, j ≤ N

2. S[i] = S[j], that is the i-th symbol of string S is equal to the j-th.

给定一个由 $N$ 个字符组成的字符串 $S$。你的任务是找出满足以下条件的整数有序对 $(i, j)$ 的数量：

1. $1 \le i, j \le N$；

2. $S[i] = S[j]$，即字符串 $S$ 的第 $i$ 个字符等于第 $j$ 个字符。

The single input line contains S, consisting of lowercase Latin letters and digits. It is guaranteed that string S in not empty and its length does not exceed 105.

单行输入包含字符串 $S$，由小写拉丁字母和数字组成。保证字符串 $S$ 非空，且其长度不超过 $10^5$。

Print a single number which represents the number of pairs i and j with the needed property. Pairs (x, y) and (y, x) should be considered different, i.e. the ordered pairs count.

输出一个整数，表示满足所需性质的索引对 $i$ 和 $j$ 的个数。有序对 $(x, y)$ 与 $(y, x)$ 被视为不同的对，即按顺序计数。