#include <bits/stdc++.h>
using namespace std;

int main(){
	int count = 0;
	int n,x;
	cin >> n >> x;
	int A[n];
	for (int i = 0; i < n; i++){
		cin >> A[i];
	}
	sort(A, A + n);
	int f = 0;
	int e = n -1;
	for (int i = 0; i < n; i++){
		cout << A[i] << " ";
	}
	cout << endl;
	while (e > f){
		if (A[f] + A[e] == x){
			count++;
			cout << f << "-" << A[f] << " " << e << "-" << A[e] << "/";
			if (A[e] == A[e - 1] and e != f){
				e--;
			}
			else if (A[f] == A[f + 1]and f != e){
				f++;
			}
			else{
				f++;
			}
		}
		else if (A[f] + A[e] > x){
			e--;
		}
		else{
			f++;
		}
	}
	//cout << count;
}