#include<iostream> // cin\cout\endl #include<cstdio> //scanf()\printf() using namespace std; int main(){ int n; cin>>n; int a[101]; for(int i=1;i<=n;i++) { cin>>a[i]; } for(int i=1;i<n;i+=2) { cout<<a[i+1]<<" "<<a[i]<<" "; } if(n%2==1) { cout<<a[n]; } }