final class FileIO {
    private let buffer: Data
    private var index: Int = 0
    
    init(fileHandle: FileHandle = FileHandle.standardInput) {
        self.buffer = try! fileHandle.readToEnd()! // 인덱스 범위 넘어가는 것 방지
    }
    
    @inline(__always) private func read() -> UInt8 {
        defer { index += 1 }
        guard index < buffer.count else { return 0 }
        
        return buffer[index]
    }
    
    @inline(__always) func readInt() -> Int {
        var sum = 0
        var now = read()
        var isPositive = true
        
        while now == 10 || now == 32 { now = read() } // 공백과 줄바꿈 무시
        if now == 45 { isPositive.toggle(); now = read() } // 음수 처리
        while now >= 48, now <= 57 {
            sum = sum * 10 + Int(now-48)
            now = read()
        }
        
        return sum * (isPositive ? 1:-1)
    }
    
    @inline(__always) func readString() -> String {
        var str = ""
        var now = read()
        
        while now == 10 || now == 32 { now = read() } // 공백과 줄바꿈 무시
        
        while now != 10 && now != 32 && now != 0 {
            str += String(bytes: [now], encoding: .ascii)!
            now = read()
        }
        
        return str
    }
}

final class IO{var b:Data,i=0;init(fh:FileHandle=FileHandle.standardInput){b=try!fh.readToEnd()!}
@inline(__always)func read()->UInt8{defer{i+=1};guard i<b.count else{return 0};return b[i]}
@inline(__always)func readInt()->Int{var s=0,n=read(),p=true;while n==10||n==32{n=read()}
if n==45{p.toggle();n=read()};while n>=48,n<=57{s=s*10+Int(n-48);n=read()};return s*(p ?1:-1)}
@inline(__always)func readString()->String{var t="",n=read();while n==10||n==32 {n=read()}
while n != 10,n != 32,n != 0{t+=String(bytes:[n],encoding:.ascii)!;n=read()};return t}}

import Foundation

final class FileIO {
    @inline(__always) private var buffer: [UInt8] = Array(FileHandle.standardInput.readDataToEndOfFile()) + [0], byteIdx = 0
    
    @inline(__always) private func readByte() -> UInt8 {
        defer { byteIdx += 1 }
        return buffer.withUnsafeBufferPointer { $0[byteIdx] }
    }
    
    @inline(__always) func readInt() -> Int {
        var number = 0, byte = readByte(), isNegative = false
        while byte == 10 || byte == 32 { byte = readByte() }
        if byte == 45 { byte = readByte(); isNegative = true }
        while 48...57 ~= byte { number = number * 10 + Int(byte - 48); byte = readByte() }
        return number * (isNegative ? -1 : 1)
    }
    
    @inline(__always) func readStringSum() -> Int {
        var byte = readByte()
        while byte == 10 || byte == 32 { byte = readByte() }
        var sum = Int(byte)
        while byte != 10 && byte != 32 && byte != 0 { byte = readByte(); sum += Int(byte) }
        return sum - Int(byte)
    }
    
    @inline(__always) private func write(_ output: String) {
        FileHandle.standardOutput.write(output.data(using: .utf8)!)
    }
}