#abc252d. [abc252_d]Distinct Trio
[abc252_d]Distinct Trio
Problem Statement
You are given a sequence of length : .
Find the number of triples that satisfy both of the following conditions.
- , , and are distinct.
Constraints
- All values in input are integers.
Input
Input is given from Standard Input in the following format:
Output
Print the answer.
Sample Input 1
4
3 1 4 1
Sample Output 1
2
The two triples satisfying the conditions are and .
Sample Input 2
10
99999 99998 99997 99996 99995 99994 99993 99992 99991 99990
Sample Output 2
120
Sample Input 3
15
3 1 4 1 5 9 2 6 5 3 5 8 9 7 9
Sample Output 3
355