#include<iostream> // cin\cout\endl #include<cstdio> //scanf()\printf() using namespace std; int main(){ int n,t; cin>>n; int a[n]; for(int i=0;i<=n-1;i++) cin>>a[i]; for(int i=0;i<n-1;i+=2){ t=a[i]; a[i]=a[i+1]; a[i+1]=t; } for(int i=0;i<n;i++) cout<<a[i]<<" "; return 0; }