Baekjoon #1922

#include<bits/stdc++.h>

using namespace std;

constexpr int MAXN = 1005;
int uf[MAXN];

int find(int x) {
    if(uf[x] < 0)return x;
    return uf[x] = find(uf[x]);
}

bool merge(int a, int b) {
    a = find(a);
    b = find(b);
    if(a == b)return false;
    uf[b] = a;
    return true;
}

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    
    vector<tuple<int, int, int>> w;
    for(int i=0;i<MAXN;i++) uf[i] = -1;
    
    int N, M; cin >> N >> M;
    for(int i=0;i<M;i++) {
        int a, b, c; cin >> a >> b >> c;
        w.emplace_back(c, a, b);
    }
    sort(w.begin(), w.end());
    
    int ans = 0;
    for(auto &[c, a, b]: w) {
        if(merge(a, b)) ans += c;
    }
    cout << ans;

    return 0;
}

import sys

def input():
    return sys.stdin.readline().rstrip()

def union(x, y):
    x = find_parent(x)
    y = find_parent(y)
    if x < y:
        parent[y] = x
    else:
        parent[x] = y

def find_parent(x):
    if x != parent[x]:
        parent[x] = find_parent(parent[x])
    return parent[x]
    
N = int(input())
M = int(input())
parent = [i for i in range(N+1)]
arr = []
ans = 0
for i in range(M):
    arr.append(list(map(int, input().split())))
arr.sort(key = lambda x : x[2])
for i in range(M):
    if find_parent(arr[i][0]) != find_parent(arr[i][1]):
        union(arr[i][0], arr[i][1])
        ans += arr[i][2]
print(ans)