class UnionFind def initialize(n) @size = Array.new(n, 1) @rank = Array.new(n, 0) @parent = [] (0..n).each do |i| @parent[i] = i end end def find(x) if @parent[x] == x x else @parent[x] = find(@parent[x]) end end def unite(x, y) x = find(x) y = find(y) return if x == y if @rank[x] < @rank[y] @parent[x] = y @size[y] += @size[x] else @parent[y] = x @size[x] += @size[y] @rank[x] += 1 if @rank[x] == @rank[y] end end def same?(x, y) find(x) == find(y) end def size(x) @size[find(x)] end end N = gets.to_i E = [] (N * (N - 1) / 2).times do a, b, c = gets.split.map(&:to_i) E << [a, b, c] end E.sort_by! { |a, b, c| c } uf = UnionFind.new(N + 1) max_r = -Float::INFINITY E.each do |a, b, c| next if uf.same?(a, b) uf.unite(a, b) max_r = c end puts max_r