/*  stream_iterator reading/writing whole lines instead of single token
*/
#include <iostream>
#include <string>
#include <iterator>
#include <algorithm>
using namespace std;
// A line is a string whose >> method inputs an entire line
class line : public string {
 friend istream& operator>>(istream& i, line& s) 
 { return getline( i, s, '\n'); }
};
int main() {  //output all lines double-spaced
 istream_iterator<line> first(cin), last;
 copy(first, last,  ostream_iterator<line>(cout, "\n\n"));
}