//import java.util.Scanner import java.io._ import java.nio.file.Files._ import java.nio.file.Path import java.util.StringTokenizer import scala.collection.immutable._ import scala.io.Codec /** * Scala implementation of a faster java.util.Scanner * See: http://codeforces.com/blog/entry/7018 */ class Scanner(reader: LineNumberReader) extends Iterable[String] with AutoCloseable { def this(reader: BufferedReader) = this(new LineNumberReader(reader)) def this(reader: Reader) = this(new BufferedReader(reader)) def this(inputStream: InputStream)(implicit codec: Codec) = this(new InputStreamReader(inputStream, codec.charSet)) def this(path: Path)(implicit codec: Codec) = this(newBufferedReader(path, codec.charSet)) def this(file: File)(implicit codec: Codec) = this(file.toPath)(codec) def this(str: String) = this(new StringReader(str)) override def iterator: Iterator[String] = for { line <- Iterator.continually(reader.readLine()).takeWhile(_ != null) tokenizer = new StringTokenizer(line) tokens <- Iterator.continually(tokenizer).takeWhile(_.hasMoreTokens) } yield tokens.nextToken() private[this] var current = iterator def hasNext: Boolean = current.hasNext @inline def next(): String = current.next() /** * This is different from Java's scanner.nextLine * The Java one is a misnomer since it actually travel to end of current line * This one actually does fetch the next line */ def nextLine(): String = { val line = reader.readLine() current = iterator line } def lineNumber: Int = reader.getLineNumber def nextString(): String = next() def nextBoolean(): Boolean = next().toBoolean def nextByte(radix: Int = 10): Byte = java.lang.Byte.parseByte(next(), radix) def nextShort(radix: Int = 10): Short = java.lang.Short.parseShort(next(), radix) def nextInt(radix: Int = 10): Int = java.lang.Integer.parseInt(next(), radix) def nextLong(radix: Int = 10): Long = java.lang.Long.parseLong(next(), radix) def nextBigInt(radix: Int = 10): BigInt = BigInt(next(), radix) def nextFloat(): Float = next().toFloat def nextDouble(): Double = next().toDouble def nextBigDecimal(): BigDecimal = BigDecimal(next()) override def close(): Unit = reader.close() } class IUnionFind(val size: Int) { private case class Node(var parent: Option[Int], var treeSize: Int) private val nodes = Array.fill[Node](size)(Node(None, treeSize = 1)) def union(t1: Int, t2: Int): IUnionFind = { if (t1 == t2) return this val root1 = root(t1) val root2 = root(t2) if (root1 == root2) return this val node1 = nodes(root1) val node2 = nodes(root2) if (node1.treeSize < node2.treeSize) { node1.parent = Some(t2) node2.treeSize += node1.treeSize } else { node2.parent = Some(t1) node1.treeSize += node2.treeSize } this } def connected(t1: Int, t2: Int): Boolean = t1 == t2 || root(t1) == root(t2) def root(t: Int): Int = nodes(t).parent match { case None => t case Some(p) => nodes(t).parent = Some(root(p)) nodes(t).parent.get } } object Main { def solve(sc: => Scanner): Unit = { val A = Array.fill(sc.nextInt() - 1)((sc.nextLong(), sc.nextLong())) .reduceLeft((x, y) => (x._1 + y._1, x._2 + y._2)) println(Math.max(A._1, A._2) - Math.abs(A._1 - A._2) + 1) } def recursive(i: Long, j: Long, k: Long): Long = { if (i <= j) 1L else recursive(i, j * k, k) + 1 } def time(s: String): Int = s.substring(0, 2).toInt * 60 + s.substring(3, 5).toInt def getPermutation(begin: Long = 0): Stream[Long] = Stream.cons(begin, getPermutation(begin + 1)) def calc(A: Array[Long]): Array[String] = { if (A.length == 0) Array.fill(0)("") else { val last = A.zipWithIndex.map(x => (x._1 - x._2, x._1)).takeWhile(x => x._1 == A.head).last._2 if (last == A.head) "%d".format(A.head) +: calc(A.zipWithIndex.map(x => (x._1 - x._2, x._1)).dropWhile(x => x._1 == A.head).map(x => x._2)) else "%d-%d".format(A.head, last) +: calc(A.zipWithIndex.map(x => (x._1 - x._2, x._1)).dropWhile(x => x._1 == A.head).map(x => x._2)) } } var memo: Map[(Long, Long), Long] = Map[(Long, Long), Long]() def recursive2(X: Set[Long], Y: Stream[Long]): Long = if (X.contains(Y.head)) X.size else recursive2(X + Y.head, Y.tail) def check(i: Int, X: String): Long = { if (X == "") 0 else check(i, X.tail) * i + X.head.toString.toLong } def shift(n: Long): Long = { if (n == 0) 0 else if (n == 1) 1 else shift(n - 1) << 1 } def unShift(n: Long): Long = { if (n == 0) 0 else unShift(n >> 1) + 1 } @scala.annotation.tailrec def gcd(i: Long, j: Long): Long = { if (i < j) gcd(j, i) else if (j == 0) i else gcd(j, i % j) } def primeFactors(i: Long): List[Long] = primeFactors_(i, 1).sorted def primeFactors_(i: Long, j: Long): List[Long] = { if (j * j > i) List.empty else if (i % j == 0) primeFactors_(i, j + 1) ++ List[Long](j, i / j) else primeFactors_(i, j + 1) } def main(args: Array[String]): Unit = { val sc: Scanner = new Scanner(System.in) solve(sc) } } object Util { def getPermutation(begin: Long = 0): Stream[Long] = Stream.cons(begin, getPermutation(begin + 1)) def getPrimeList: Stream[Long] = getPrimeListRecursive(getPermutation(begin = 2)) private def getPrimeListRecursive(A: Stream[Long]): Stream[Long] = Stream.cons(A.head, getPrimeListRecursive(A.tail.filter(_ % A.head != 0))) def fib(a: Long = 0, b: Long = 1, mod: Long = Long.MaxValue): Stream[Long] = a #:: fib(b % mod, (a + b) % mod, mod) } object ArabicRoman { type =?>[A, B] = PartialFunction[A, B] val codeTable = List( (1000, "M"), (900, "CM"), (500, "D"), (400, "CD"), (100, "C"), (90, "XC"), (50, "L"), (40, "XL"), (10, "X"), (9, "IX"), (5, "V"), (4, "IV"), (1, "I")) val arabicToRoman: Int =?> String = { case src if src >= 1 && src <= 3999 => def convert(left: Int, cont: String = "", code: List[(Int, String)] = codeTable): String = { val (unitVal, unitChar) = code.head left - unitVal match { case n if n == 0 => cont + unitChar case n if n > 0 => convert(n, cont + unitChar, code) case _ => convert(left, cont, code.tail) } } convert(src) } val romanToArabic: String =?> Int = { case src if Option(src).exists { s => { s.nonEmpty && """[^MDCLXVI]""".r.findFirstMatchIn(s.toUpperCase).isEmpty } } => def convert(left: String, cont: Int = 0, code: List[(Int, String)] = codeTable): Int = { val (unitVal, unitChar) = code.head left.splitAt(unitChar.length) match { case ("", _) => cont case (`unitChar`, tail) => convert(tail, cont + unitVal, code) case _ => convert(left, cont, code.tail) } } convert(src.toUpperCase()) } }