import java.io.BufferedReader import java.io.InputStream import java.io.InputStreamReader import java.lang.AssertionError import java.util.* import kotlin.math.abs import kotlin.math.max import kotlin.math.min val MOD = 1_000_000_007 class Solver(stream: InputStream, private val out: java.io.PrintWriter) { private val reader = BufferedReader(InputStreamReader(stream), 32768) fun solve() { val N = nl() val ans = when(N){ 1L -> 12L 2L -> 65L else -> { val center = (6*N/2 + 1) val half = (6*N+1)*N + 2*N*N + N*(N-1)/2 + // 2N .. 3N N half*2 + center } } out.println(ans) // val que = ArrayDeque>() // val N = 11 // val MAX = 71 // val visit = Array(MAX){BooleanArray(MAX)} // val C = IntArray(N + 1) // fun add(x: Int, y: Int, cnt: Int) { // if (!visit[x][y]) { // visit[x][y] = true // que.add(Triple(x, y, cnt)) // C[cnt]++ // } // } // add(MAX/2, MAX/2, 0) // // for (i in 0 until N) { // visit.forEach { it.fill(false) } // while (que.isNotEmpty() && que.peekFirst().third == i) { // val v = que.pollFirst() // val tt = arrayOf(intArrayOf(2, 3), intArrayOf(0, 3)) // for (j in 0 until 2) { // for (x in 0 until 2) { // for (y in 0 until 2) { // for (z in 0 until 2) { // val a = if (z == 0) tt[j].clone() else tt[j].reversed().toIntArray() // if (x == 1) a[0] *= -1 // if (y == 1) a[1] *= -1 // val nx = v.first + a[0] // val ny = v.second + a[1] // add(nx, ny, v.third + 1) // } // } // } // } // } // } // // debugDim(visit) // debug{"${C[N]}"} } private val isDebug = try { // なんか本番でエラーでる System.getenv("MY_DEBUG") != null } catch (t: Throwable) { false } private var tokenizer: StringTokenizer? = null private fun next(): String { while (tokenizer == null || !tokenizer!!.hasMoreTokens()) { tokenizer = StringTokenizer(reader.readLine()) } return tokenizer!!.nextToken() } private fun ni() = next().toInt() private fun nl() = next().toLong() private fun ns() = next() private fun na(n: Int, offset: Int = 0): IntArray { return IntArray(n) { ni() + offset } } private fun nal(n: Int, offset: Int = 0): LongArray { val res = LongArray(n) for (i in 0 until n) { res[i] = nl() + offset } return res } private fun na2(n: Int, offset: Int = 0): Array { val a = Array(2){IntArray(n)} for (i in 0 until n) { for (e in a) { e[i] = ni() + offset } } return a } private inline fun debug(msg: () -> String) { if (isDebug) System.err.println(msg()) } /** * コーナーケースでエラー出たりするので、debug(dp[1])のように添え字付きの場合はdebug{}をつかうこと */ private inline fun debug(a: LongArray) { debug { a.joinToString(" ") } } private inline fun debug(a: IntArray) { debug { a.joinToString(" ") } } private inline fun debug(a: BooleanArray) { debug { toString(a) } } private inline fun toString(a: BooleanArray) = run{a.map { if (it) 1 else 0 }.joinToString("")} private inline fun debugDim(A: Array) { if (isDebug) { for (a in A) { debug(a) } } } private inline fun debugDim(A: Array) { if (isDebug) { for (a in A) { debug(a) } } } private inline fun debugDim(A: Array) { if (isDebug) { for (a in A) { debug(a) } } } /** * 勝手にimport消されるのを防ぎたい */ private fun hoge() { min(1, 2) max(1, 2) abs(-10) } private inline fun assert(b: Boolean) = run{if (!b) throw AssertionError()} private inline fun assert(b: Boolean, f: () -> String) = run{if (!b) throw AssertionError(f())} } fun main() { val out = java.io.PrintWriter(System.out) Solver(System.`in`, out).solve() out.flush() }