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