#include <iostream> using namespace std; int main(){ int n; int a[108]; cin>>n; for(int i=0;i<n;i++) cin>> a[i]; int m = n/2; for(int i=0;i<m;i++)// 0-1 2-3 4-5 6-7 { //a[i] -- a[i+1] int left= i*2; int right = i*2+1; int tmp; tmp = a[left]; a[left] = a[right]; a[right] = tmp; } for(int i=0;i<n;i++) cout<< a[i]<<" "; return 0; } /* Input 3 1 2 3 Output 2 1 3 */