# include<iostream> using namespace std; int main(){ int z[100],n,s,q; cin>>n; for(int i=0;i<n;i++){ cin>>z[i];} for(int i=0;i<n-1;i+=2){ q=z[i]; z[i]=z[i+1]; z[i+1]=q;} for(int i=0;i<n;i++){ cout<<z[i]; if(i!=n-1) cout<<' '; } cout<<endl; return 0;}