#include <bits/stdc++.h> using namespace std; int main(){ int n; cin >> n; int a[108]; for(int i = 1;i <= n;i++) { cin >> a[i]; } for(int i = 1;i < n;i = i + 2) { swap(a[i], a[i + 1]); } for(int i = 1;i <= n;i++) { cout << a[i] <<" "; } return 0; }