#include <iostream> using namespace std; int main(){ int a[100],i,n,t; cin>>n; for(i=0;i<n;i++){ cin>>a[i]; } for(i=0;i<n-1;i+=2){ t=a[i]; a[i]=a[i+1]; a[i+1]=t; } for(i=0;i<n;i++){ cout<<a[i]; if(i!=n-1){ cout<<" "; } } cout<<endl; }