#include<bits/stdc++.h> using namespace std; int main(){ int n; cin>>n; int a[n];//0,1,2...,n-1 //a[5] 0,1,2,3,4 //b[6] 0,1,2,3,4,5 for(int i=0;i<=n-1;i++){ cin>>a[i]; } int b; for(int i=0;i<=n-2;i=i+2){ b=a[i]; a[i]=a[i+1]; a[i+1]=b; } for(int i=0;i<=n-1;i++){ cout<<a[i]<<" "; } }