#include <iostream> using namespace std; int main() { int n; cin >> n; int arr[100]; for (int i = 0; i < n; i++) { cin >> arr[i]; } for (int i = 0; i < n - 1; i += 2) { int temp = arr[i]; arr[i] = arr[i + 1]; arr[i + 1] = temp; } for (int i = 0; i < n; i++) { cout << arr[i] << " "; } cout << endl; return 0; }