Score : $400$ points
You are given a sequence of length $N$: $A=(A_1,A_2,\ldots,A_N)$.
Find the number of triples $(i,j,k)$ that satisfy both of the following conditions.
Input is given from Standard Input in the following format:
$N$ $A_1$ $A_2$ $\ldots$ $A_N$
Print the answer.
4 3 1 4 1
2
The two triples $(i,j,k)$ satisfying the conditions are $(1,2,3)$ and $(1,3,4)$.
10 99999 99998 99997 99996 99995 99994 99993 99992 99991 99990
120
15 3 1 4 1 5 9 2 6 5 3 5 8 9 7 9
355