#include <iostream>
#include <vector>
using namespace std;
int main(int argc, char* argv[])
{
	int N,i,j;
	cin>>N;
	vector<int> P(N);
	vector<vector<int>> A(N);
	int MaxP=0;
	for (i=0;i<N;i++){
		cin>>P[i];
		int B;
		for (j=0;j<P[i];j++){
			cin>>B;
			A[i].push_back(B);
		}
		if (MaxP<P[i]){
			MaxP=P[i];
		}
	}
	for (i=0;i<N;i++){
		while (A[i].size()<MaxP){
			A[i].push_back(-1);
		}
	}
	for (j=0;j<MaxP;j++){
		for (i=0;i<N;i++){
			if (A[i][j]>=0){
				cout<<A[i][j];
				//if (i<N&&j<MaxP-1){
					cout<<" ";
				//}
			}
		}
	}
	cout<<endl;
	return 0;
}