SP8372 TSUM - Triple Sums
Description
You're given a sequence **s** of **N** distinct integers.
Consider all the possible sums of three integers from the sequence at three different indicies.
For each obtainable sum output the number of different triples of indicies that generate it.
**Constraints:**
N
Input Format
The first line of input contains a single integer N.
Each of the next N lines contain an element of s.
Output Format
Print the solution for each possible sum in the following format:
sum\_value : number\_of\_triples
Smaller sum values should be printed first.