func main()
	var n: int :: cui@inputInt()
	var s: [][]char :: #[n][]char
	
	for i(0, n - 1)
		do s[i] :: cui@input()
	end for
	
	var dic: dict<[]char, bool> :: #dict<[]char, bool>
	
	for i(0, n - 1)
		for j(0, n - 1)
			if(i <> j)
				do dic.add(s[i] ~ s[j], true)
			end if
		end for
	end for
	
	var ans: int :: ^dic
	do cui@print("\{ans}\n")
end func