@main
struct Day6 {
    let input = [3,3,2,1,4,1,1,2,3,1,1,2,1,2,1,1,1,1,1,1,4,1,1,5,2,1,1,2,1,1,1,3,5,1,5,5,1,1,1,1,3,1,1,3,2,1,1,1,1,1,1,4,1,1,1,1,1,1,1,4,1,3,3,1,1,3,1,3,1,2,1,3,1,1,4,1,2,4,4,5,1,1,1,1,1,1,4,1,5,1,1,5,1,1,3,3,1,3,2,5,2,4,1,4,1,2,4,5,1,1,5,1,1,1,4,1,1,5,2,1,1,5,1,1,1,5,1,1,1,1,1,3,1,5,3,2,1,1,2,2,1,2,1,1,5,1,1,4,5,1,4,3,1,1,1,1,1,1,5,1,1,1,5,2,1,1,1,5,1,1,1,4,4,2,1,1,1,1,1,1,1,3,1,1,4,4,1,4,1,1,5,3,1,1,1,5,2,2,4,2,1,1,3,1,5,5,1,1,1,4,1,5,1,1,1,4,3,3,3,1,3,1,5,1,4,2,1,1,5,1,1,1,5,5,1,1,2,1,1,1,3,1,1,1,2,3,1,2,2,3,1,3,1,1,4,1,1,2,1,1,1,1,3,5,1,1,2,1,1,1,4,1,1,1,1,1,2,4,1,1,5,3,1,1,1,2,2,2,1,5,1,3,5,3,1,1,4,1,1,4]

    var population: [Int] = .init(repeating: 0, count: 9)

    func step() -> [Int] {
        var result = Array(repeating: 0, count: 9)
        for (age, count) in population.enumerated() {
            if age == 0 {
                result[6] += count
                result[8] += count
            } else {
                result[age - 1] += count
            }
        }
                return result
    }

    mutating func run() {
        for age in input {
            population[age] += 1
        }

        for day in 0..<256 {
            population = step()
        }

        print(population.reduce(0) { $0 + $1 })
    }

    static func main() {
        var x = Self()
            x.run()
    }
}