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