#include <iostream> using namespace std; int main(){ int a[10000],b[10000],n,i,c; cin>>n; for(i=0;i<n;i++){ cin>>a[i]; }for(i=0;i<n-1;i=i+2){ c=a[i]; a[i]=a[i+1]; a[i+1]=c; }for(i=0;i<n;i++){ cout<<a[i]<<" "; } return 0; }