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