#include<iostream> // cin\cout\endl #include<cstdio> //scanf()\printf() #include<cstring> // strcpy()\strcat()\strcmp()\strlen()\memset() #include<cmath> //sqrt()\pow()\abs()\ceil()\floor()\max()\min() using namespace std; int main(){ int a[101],n; cin>>n; for(int i=1;i<=n;i++){ cin>>a[i]; } for(int i=1;i<n;i+=2){ cout<<a[i+1]<<" "<<a[i]<<" "; } if(n%2){ cout<<n; } return 0; }