Two Sum Pair Finder

You are given a list of integers and a target integer. Your task is to determine whether there exist two distinct numbers in the list that sum up to the target value.

The condition for a valid solution is that the list must consist entirely of integers. If any non-integer is present, the program should output an error message stating "All elements in the list must be integers."

Formally, given a list \(nums\) and an integer \(target\), you need to check if there exist indices \(i\) and \(j\) (\(i \neq j\)) such that:

\(nums[i] + nums[j] = target\)

Note: You must read the input from stdin and write the result to stdout. The output should be either True or False depending on whether such a pair exists.

inputFormat

The input consists of three lines:

1. The first line contains a single integer \(n\) representing the number of elements in the list.
2. The second line contains \(n\) space-separated integers.
3. The third line contains a single integer representing the target value.

outputFormat

Output a single line to stdout containing either True if there exist two distinct numbers that sum up to the target, or False otherwise.

5
1 2 3 4 5
9

True