# include<iostream> using namespace std; int main(){ int n,a[1001],b[1001],s=0; cin>>n; for(int i=0;i<n;i++) cin>>a[i]; for(int i=0;i<=n-1;i+=2){ if(i!=n-1) cout<<a[i+1]<<" "<<a[i]<<" "; else cout<<a[i]; } return 0; }