#include <fstream.h>

static const int nlmax = 2;

int
main(int argc, char *argv[])
{
	int more=1;
	int nlcount=0;
	while (more) {
		char c;
		cin.read(&c,1);
		if (cin.eof() || !cin.good()) break;

		if (c == '\n') {
			if (++nlcount > nlmax) continue;
		}
		else {
			nlcount=0;
		}
		cout.write(&c,1);
	}
	return 0;
}