#include <iostream>
using namespace std;
int main() {
int n;
cin >> n;
int a[21000];
for (int i = 0; i < n; ++i){
cin >> a[i];
}
for (int i = 0; i < n; i += 2){
int temp = a[i];
a[i] = a[i + 1];
a[i + 1] = temp;
}
for (int i = 0; i < n; ++i){
cout << a[i] << " ";
}
cout << endl;
}
