func dfs(_ n: Int, _ m: Int, _ nums: [Int], _ visited: inout [Bool], _ result: inout [Int]) {
    if result.count == m {
        print(result.map{String($0)}.joined(separator: " "))
        return
    }

    var prev = -1
    for i in 0..<n {
        if !visited[i] && nums[i] != prev {
            visited[i] = true
            result.append(nums[i])
            dfs(n,m,nums,&visited,&result)
            _ = result.popLast()
            visited[i] = false
            prev = nums[i]
        }
    }
}

if let input1 = readLine(), let NM = input1.split(separator: " ").map({Int($0)}) as? [Int], NM.count == 2 {
    let N = NM[0]
    let M = NM[1]

    if let input2 = readLine(), let nums = input2.split(separator: " ").map({Int($0)}) as? [Int], nums.count == N {
        var visited:[Bool] = Array(repeating: false, count: N)
        var result: [Int] = []
        dfs(N, M, nums.sorted(), &visited, &result)
    }
}