Two Sum Problem

You are given a list of n integers and a target integer T. Your task is to find two distinct indices i and j (0-indexed) such that:

\(a_i + a_j = T\)

If there are multiple solutions, return the first valid pair encountered. If no such pair exists, output None.

inputFormat

The input is read from standard input (stdin) and consists of three lines:

• The first line contains an integer n denoting the number of elements in the list.
• The second line contains n space-separated integers.
• The third line contains an integer T denoting the target sum.

outputFormat

If a valid pair is found, output two space-separated integers denoting their 0-indexed positions. Otherwise, output None.

4
2 7 11 15
9

0 1