import Foundation

let (w, h) = (101, 103)

infix operator %%: MultiplicationPrecedence
func %%<T: BinaryInteger>(lhs: T, rhs: T) -> T {
    return (lhs % rhs + rhs) % rhs
}

struct Robot : CustomStringConvertible {
    var (x, y): (Int, Int)
    let (vx, vy): (Int, Int)
    var description: String { return "p=(\(x), \(y)) v=(\(vx), \(vy))" }

    mutating func move() {
        x = (x + vx) %% w
        y = (y + vy) %% h
    }
}

func readInput(_ filePath: String) throws -> [Robot] {
    let robot = try Regex(#"p=([0-9]+),([0-9]+) v=([0-9-]+),([0-9-]+)"#)
    var robots: [Robot] = []
    let content = try String(contentsOfFile: filePath, encoding: .ascii)
    content.split(separator: "\n").forEach { line in
        if let m = line.wholeMatch(of: robot) {
            robots.append(Robot(
                x: Int(m.output[1].substring!)!,
                y: Int(m.output[2].substring!)!,
                vx: Int(m.output[3].substring!)!,
                vy: Int(m.output[4].substring!)!
            ))
        }
    }
    return robots
}

var robots = try readInput(CommandLine.arguments[1])
for _ in 0..<100 {
    for i in 0..<robots.count {
        robots[i].move()
    }
}
var (ul, ur, ll, lr) = (0, 0, 0, 0)
for robot in robots {
    if robot.x < w/2 && robot.y < h/2 { ul += 1 }
    if robot.x > w/2 && robot.y < h/2 { ur += 1 }
    if robot.x < w/2 && robot.y > h/2 { ll += 1 }
    if robot.x > w/2 && robot.y > h/2 { lr += 1 }
}
print("\(ul) x \(ur) x \(ll) x \(lr) = \(ul * ur * ll * lr)")