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