int v; //邻接点

int weight; //邻接边权重

AdjNode(int v, int weight) : v(v), weight(weight) {}

Prim() {}

~Prim() {}

/* 若图连通返回true，否则返回false，用pMstWeight传出最小生成树权重。*/

bool prim(vector<AdjNode> *graph, int n, int *pMstWeight);

//优先队列使用的结构体

struct Node {

int v;

int dist;

Node(int v, int dist) : v(v), dist(dist) {}

};

struct cmp {

bool operator() (Node& a, Node& b) {

return a.dist > b.dist;

}

};

int *dist = new int[n];

fill(dist, dist + n, NO_VALUE);

int src = 0;

dist[src] = 0;

priority_queue<Node, vector<Node>, cmp> q;

q.push(Node(src, dist[src]));

int vcount = 0;

*pMstWeight = 0;

while (!q.empty()) {

int minV = q.top().v;

q.pop();

if (minV != src && !dist[minV]) continue;

(*pMstWeight) += dist[minV];

dist[minV] = 0;

vcount++;

for (AdjNode adjNode : graph[minV]) {

int adjVertex = adjNode.v;

int adjWeight = adjNode.weight;

if (dist[adjVertex]) {

if (adjWeight < dist[adjVertex] || dist[adjVertex] == NO_VALUE) {

dist[adjVertex] = adjWeight;

q.push(Node(adjVertex, dist[adjVertex]));

}

}

}

} //while

free(dist);

return vcount == n;

int n, m;

scanf("%d %d", &n, &m);

vector<AdjNode> *graph = new vector<AdjNode>[n];

int x, y, z;

for (int i = 0; i < m; i++) {

scanf("%d %d %d", &x, &y, &z);

x--; y--;

graph[x].push_back(AdjNode(y, z));

graph[y].push_back(AdjNode(x, z));

}

Prim prim;

int mstWeight;

if (prim.prim(graph, n, &mstWeight)) {

printf("%d", mstWeight);

}

else printf("orz");

for (int i = 0; i < n; i++) {

vector<AdjNode>().swap(graph[i]);

}

return 0;

}