#include <stdio.h>

int main(){
    int n, a[100], i, t;
    
    scanf("%d", &n);
    
    for(i = 0; i < n; i++)
    scanf("%d", &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++)
    primtf("%d",a[i]);
    
    return 0;
}