#include <iostream>
#include <iterator>
#include <string>
int main() {
for( auto it=++std::istream_iterator<std::string>(std::cin); it!=std::istream_iterator<std::string>(); std::advance(it,2) )
{
std::cout << *it << " ";
}
std::cout << std::endl;
return 0;
}
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