#include <iostream> #include <cstdio> using namespace std; int main() { int n,a[101],i,q; cin>>n; for (int i=0;i<n;i++) cin>>a[i]; for (int i=0;i<n-1;i+=2){ q=a[i]; a[i]=a[i+1]; a[i+1]=q;} for (int i=0;i<n;i++){ cout<<a[i]; if(i!=n-1) cout<<' ';} cout<<endl; return 0; }