# include<iostream> using namespace std; int main(){ int n,c=0,w; cin>>n; int a[n]; for(int i=0;i<n;i++){ cin>>a[i]; } w=n; w/=2; w*=2; for(int i=0;i<w;i+=2){ c=a[i]; a[i]=a[i+1]; a[i+1]=c; } for(int i=0;i<n;i++){ cout<<a[i]<<" "; } return 0; }