#include <iostream>
#include <sstream>
int main()
{
std::istringstream infile ("100 90 80 78 67 56 20 78 99 54 89 100 90 80");
for(int i = 0, num; infile >> num; ++i)
{
if(i%3 == 0)
{
std::cout << num << " " << std::flush;
}
}
}
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