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