#include<iostream> using namespace std; //数组 //定义数组 int c[10]; int b; int main() { int n ; cin>>n; for (int i = 1;i <= n;i++) { cin>>c[i]; } for (int i = 1;i <= n;i++) { if (i % 2 == 0) { cout<<c[i]<<" "<<c[i-1]<<" "; } } if (n % 2 != 0) { cout<<c[n]; } return 0; }