package main

import . "fmt"
import . "slices"
import st "strings"

func main() {
	var n int
	Scan(&n)
	ss:=make([][]string,1e2)
	for ;n>0;n-- {
		var p int
		Scan(&p)
		for i:=0;i<p;i++ {
			var a string
			Scan(&a)
			ss[i]=append(ss[i],a)
		}
	}
	ans := []any{}
	for _, s :=range DeleteFunc(ss, func(sa []string) bool { return len(sa)==0 }) {
		ans = append(ans, st.Join(s, " "))
	}
	Println(ans...)
}