#include<bits/stdc++.h>
using namespace std;
int main() {
    unordered_map<int,int> hash;
    int n;
    cin>>n;
    int a[n];
    for(int i=0;i<n;i++)
    {
        cin>>a[i];
        hash[a[i]]=1;
    }
    int target;
    cin>>target;
    sort(a,a+n);
    
    for(int i=0;i<n;i++)
    {
        if(hash[target-a[i]]==1)
        {
            hash[target-a[i]]=0;
            hash[a[i]]=0;
            cout<<a[i]<<" and "<<target-a[i]<<endl;
        }
    }
	return 0;
}