Pair with Sum

Given an array of integers and an integer (k), determine whether there exist two distinct indices (i) and (j) such that (a_i + a_j = k). More formally, given an array ({a_1, a_2, \ldots, a_n}) and an integer (k), check if there exist indices (i \neq j) satisfying (a_i + a_j = k). This problem tests your ability to use efficient lookup techniques to solve the two-sum problem.

inputFormat

The input is given via standard input (stdin) and consists of two lines. The first line contains two space-separated integers (n) and (k), where (n) is the number of elements in the array and (k) is the target sum. The second line contains (n) space-separated integers representing the elements of the array.

outputFormat

Output a single line to standard output (stdout): print true if there exists a pair of distinct elements whose sum is equal to (k), otherwise print false.## sample

4 17
10 15 3 7

true