func dfs(_ N: Int, _ M: Int, _ nums: [Int], _ current: Int, _ result: inout [Int]) {
    if result.count == M {
        for i in 0..<M {
            print(result[i], terminator: " ")
        }
        print()
        return
    }

    var prev = -1
    for i in current..<N {
        if prev != nums[i] {
            result.append(nums[i])
            dfs(N,M,nums,i,&result)
            _ = result.popLast()
            prev = nums[i]
        }
    }
}

if let line1 = readLine(), let NM = line1.split(separator: " ").compactMap({Int($0)}) as? [Int], NM.count == 2 {
    let N = NM[0]
    let M = NM[1]
    
    if let line2 = readLine(), let nums = line2.split(separator: " ").compactMap({Int($0)}) as? [Int], nums.count == N {
        var result: [Int] = [];
        dfs(N,M,nums.sorted(),0,&result)
    }
}