import Foundation

struct Point : Hashable {
    let x: Int
    let y: Int
}

func readInput(_ filePath: String) throws -> (Int, Int, [Character: [Point]]) {
    let content = try String(contentsOfFile: filePath, encoding: .ascii)
    let lines = content.split(separator: "\n").map(Array.init)
    let antennas = lines.enumerated().flatMap { i, line in
        line.enumerated().compactMap { j, cell in
            cell == "." ? nil : (cell, i, j)
        }
    }
    var map: [Character: [Point]] = [:]
    for (type, i, j) in antennas {
        let current = map[type, default: []]
        map[type] = current + [Point(x: i, y: j)]
    }
    return (lines.count, lines[0].count, map)
}

func nodes(_ antennas: [Point]) -> Set<Point> {
    var nodes: Set<Point> = []
    for i in 0..<antennas.count {
        for j in i+1..<antennas.count {
            let (a, b) = (antennas[i], antennas[j])
            nodes.insert(Point(x: 2*a.x - b.x, y: 2*a.y - b.y))
            nodes.insert(Point(x: 2*b.x - a.x, y: 2*b.y - a.y))
        }
    }
    return nodes
}

let (height, width, antennas) = try readInput(CommandLine.arguments[1])
let answer = antennas
    .map { c, points in nodes(points) }
    .reduce(Set([]), { acc, x in acc.union(x) })
    .filter { p in p.x >= 0 && p.y >= 0 && p.x < height && p.y < width }
    .count
print(answer)