fun main(args: Array<String>) {
    val (_, X) = readLine()!!.split(" ").map(String::toInt)
    val nums = readLine()!!.split(" ").map(String::toInt)
    val numCounts = nums.groupingBy { it }.eachCount()

    println(nums.sumBy { numCounts[X - it] ?: 0 })
}