#include<bits/stdc++.h> using namespace std; int main(){ int n,a[101]; cin>>n; for(int i = 1;i<=n;i++){ cin>>a[i]; } for(int i = 1;i<n;i+=2){ int t=a[i]; a[i]=a[i+1]; a[i+1]=t; } for(int i = 1;i<=n;i++){ cout<<a[i]<<" "; } return 0; }