Problem: Find the sum of weights of edges of the Minimum Spanning Tree for a given weighted undirected graph G = (V, E).

Constraints

* 1 ≤ |V| ≤ 10,000
* 0 ≤ |E| ≤ 100,000
* 0 ≤ wi ≤ 10,000
* The graph is connected
* There are no parallel edges
* There are no self-loops

Input


|V| |E|
s0 t0 w0
s1 t1 w1
:
s|E|-1 t|E|-1 w|E|-1


, where |V| is the number of vertices and |E| is the number of edges in the graph. The graph vertices are named with the numbers 0, 1,..., |V|-1 respectively.

si and ti represent source and target verticess of i-th edge (undirected) and wi represents the weight of the i-th edge.

Output

Print the sum of the weights of the Minimum Spanning Tree.

Examples

Input

4 6
0 1 2
1 2 1
2 3 1
3 0 1
0 2 3
1 3 5


Output

3


Input

6 9
0 1 1
0 2 3
1 2 1
1 3 7
2 4 1
1 4 3
3 4 1
3 5 1
4 5 6


Output

5

Solution (in JAVA):

Solution:

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.util.Arrays;
import java.util.InputMismatchException;
import java.util.StringTokenizer;

public class Main {

	public static void main(String[] args) throws IOException {
		InputStream inputStream = System.in;
		OutputStream outputStream = System.out;
		InputReader in = new InputReader(inputStream);
		PrintWriter out = new PrintWriter(outputStream);
		TaskX solver = new TaskX();
		solver.solve(1, in, out);
		out.close();
	}

	static int INF = 1 << 30;
	static int modP = 1000000007;

	static class TaskX {
		public void solve(int testNumber, InputReader in, PrintWriter out) {

			int v = in.nextInt(), e = in.nextInt();
			E[] es = new E[e];
			for (int i = 0; i < e; i++) {
				int s = in.nextInt(), t = in.nextInt(), w = in.nextInt();
				es[i] = new E(s, t, w);
			}

			Arrays.sort(es, (a, b) -> a.weight - b.weight);
			DisjointSet set = new DisjointSet(v);
			int ans = 0;
			for (int i = 0; i < e; i++) {
				E edge = es[i];
				if (!set.same(edge.from, edge.to)) {
					set.unite(edge.from, edge.to);
					ans += edge.weight;
				}
			}

			out.println(ans);
		}

		public class DisjointSet {

			int[] p, rank;

			public DisjointSet(int size) {
				p = new int[size];
				rank = new int[size];

				for (int j = 0; j < size; j++) {
					makeSet(j);
				}
			}

			private void makeSet(int x) {
				p[x] = x;
				rank[x] = 0;
			}

			public int findSet(int x) {
				return p[x] == x ? x : findSet(p[x]);
			}

			public void link(int x, int y) {
				if (rank[x] > rank[y]) {
					p[y] = x;
				} else if (rank[x] < rank[y]) {
					p[x] = y;
				} else if (rank[x] == rank[y]) {
					p[x] = y;
					rank[y]++;
				}
			}

			public void unite(int x, int y) {
				link(findSet(x), findSet(y));
			}

			public boolean same(int x, int y) {
				return findSet(x) == findSet(y);
			}
		}
	}


	static class E {
		int from, to, weight;
		E (int from, int to, int weight) {
			this.from = from;
			this.to = to;
			this.weight = weight;
		}
	}

	static class InputReader {
		BufferedReader in;
		StringTokenizer tok;

		public String nextString() {
			while (!tok.hasMoreTokens()) {
				try {
					tok = new StringTokenizer(in.readLine(), " ");
				} catch (IOException e) {
					throw new InputMismatchException();
				}
			}
			return tok.nextToken();
		}

		public int nextInt() {
			return Integer.parseInt(nextString());
		}

		public long nextLong() {
			return Long.parseLong(nextString());
		}

		public double nextDouble() {
			return Double.parseDouble(nextString());
		}

		public int[] nextIntArray(int n) {
			int[] res = new int[n];
			for (int i = 0; i < n; i++) {
				res[i] = nextInt();
			}
			return res;
		}

		public long[] nextLongArray(int n) {
			long[] res = new long[n];
			for (int i = 0; i < n; i++) {
				res[i] = nextLong();
			}
			return res;
		}

		public InputReader(InputStream inputStream) {
			in = new BufferedReader(new InputStreamReader(inputStream));
			tok = new StringTokenizer("");
		}

	}

}