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