#include <iostream>
using namespace std;
int main() {
int mas[10000], i, n;
cin >> n;
for (i = 0; i < n; i++)
cin >> mas[i];
for (i = 0; i < n; i=i+3)
cout << mas[i] << " ";
}
I2luY2x1ZGUgPGlvc3RyZWFtPgp1c2luZyBuYW1lc3BhY2Ugc3RkOwoKaW50IG1haW4oKSB7CglpbnQgbWFzWzEwMDAwXSwgaSwgbjsKCWNpbiA+PiBuOwoJZm9yIChpID0gMDsgaSA8IG47IGkrKykKCQljaW4gPj4gbWFzW2ldOwoJZm9yIChpID0gMDsgaSA8IG47IGk9aSszKQoJCWNvdXQgPDwgbWFzW2ldIDw8ICIgIjsKfQ==