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