#include<bits/stdc++.h> using namespace std; int main (){ int n; cin >> n; int a[1000001]; for(int i = 1;i <= n;i++) { cin >> a[i]; } for(int i = 2;i <= n;i+=2) { int temp; temp = a[i]; a[i] = a[i - 1]; a[i - 1] = temp; } for(int i = 1;i <= n;i++) { cout << a[i] <<" "; } return 0; }