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