#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[100]; int n,s=0; cin>>n; for(int z=0;z<n;z++){ cin>>a[z]; } for(int z=0;z<n-1;z+=2){ s=a[z+1]; a[z+1]=a[z]; a[z]=s; } for(int z=0;z<n;z++){ cout<<a[z]<<" "; } return 0; }