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