export {};
const input = require("fs").readFileSync(0).toString().trim().split("\n");
const [V, E]: number[] = input[0].split(" ").map(Number);

let edges: number[][] = [];
for(let edge of input.slice(1)) edges.push(edge.split(" ").map(Number));

let parent: number[] = Array.from({length: V+1}, (_, i) => i);
let rank: number[] = new Array(V+1).fill(0);

const find = (x: number): number => {
    if(x !== parent[x]) return parent[x] = find(parent[x]);
    return parent[x];
}

const union = (x: number, y: number) => {
    x = find(x);
    y = find(y);

    if(x === y) return;

    if(rank[x] < rank[y]) [x, y] = [y, x];

    parent[y] = x;
    if(rank[x] === rank[y]) rank[x]++;
}

const kruskal = (): number => {
    edges.sort((a,b) => a[2] - b[2]);

    let total_weight = 0;
    let edge_count = 0;

    for(let edge of edges) {
        const [u, v, w]: number[] = edge;

        if(find(u) !== find(v)) {
            union(u, v);
            total_weight += w;
            edge_count += 1;

            if(edge_count === V-1) break;
        }
    }

    return total_weight;
}

console.log(kruskal());