class Graph:
    def __init__(self):
        self.edges = []
        self.vertices = set()

    def add_edge(self, u, v, w):
        self.edges.append((w, u, v))
        self.vertices.add(u)
        self.vertices.add(v)

    def find(self, parent, i):
        if parent[i] == i:
            return i
        return self.find(parent, parent[i])

    def union(self, parent, rank, x, y):
        if rank[x] < rank[y]:
            parent[x] = y
        elif rank[x] > rank[y]:
            parent[y] = x
        else:
            parent[y] = x
            rank[x] += 1

    def kruskal_mst(self):
        self.edges.sort()
        parent = {}
        rank = {}

        for v in self.vertices:
            parent[v] = v
            rank[v] = 0

        mst = []
        total_cost = 0

        for w, u, v in self.edges:
            x = self.find(parent, u)
            y = self.find(parent, v)

            if x != y:
                mst.append((u, v, w))
                total_cost += w
                self.union(parent, rank, x, y)

        print("\nEdges in Minimum Cost Spanning Tree:")
        for u, v, w in mst:
            print(f"{u} - {v} = {w}")

        print("Total cost of MST =", total_cost)


# ---------------- DRIVER CODE ----------------

g = Graph()

e = int(input("Enter number of edges: "))

print("Enter edges in format: ab 3")
for _ in range(e):
    edge, weight = input().split()
    u = edge[0]
    v = edge[1]
    w = int(weight)
    g.add_edge(u, v, w)

g.kruskal_mst()