#include <bits/stdc++.h> using namespace std; int a[1001]; int main() { int n; cin>>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]<<" "; } return 0; }