import Foundation

func readInput(_ filePath: String) throws -> [Int] {
    return try String(contentsOfFile: filePath, encoding: .ascii)
        .split(separator: "\n").compactMap { Int($0) }
}

func haggle(_ seeds: [Int]) -> [[Int]: [Int: Int]] {
    var bananas: [[Int]: [Int: Int]] = [:]
    for (monkey, seed) in seeds.enumerated() {
        var prevs = [Int.min, Int.min, Int.min, Int.min]
        var lastPrice = seed
        for _ in 0..<2000 {
            var price = ((lastPrice << 6) ^ lastPrice) & 16777215
            price = ((price >> 5) ^ price)
            price = ((price << 11) ^ price) & 16777215
            prevs[0] = prevs[1]; prevs[1] = prevs[2]; prevs[2] = prevs[3]
            prevs[3] = (price % 10) - (lastPrice % 10)
            lastPrice = price
            if let _ = bananas[prevs, default: [:]][monkey] { continue }
            bananas[prevs, default: [:]][monkey] = price % 10
        }
    }
    return bananas
}

let seeds = try readInput(CommandLine.arguments[1])
let bananas = haggle(seeds)
print(bananas.values.map { $0.values.reduce(0, +) }.max() ?? "ERROR")