#include <bits/stdc++.h>

using namespace std;

typedef pair<int, int> pii;
typedef pair<int, pair<int, int> > piii;
typedef long long ll;
const int N = 2000086, MOD = 998244353, INF = 0x3f3f3f3f;
ll res;
int n, m, cnt, w[N];

// int e[N], ne[N], h[N], idx;
// void add(int a, int b, int c) { e[idx] = b, ne[idx] = h[a], w[idx] = c, h[a] = idx++; }
struct Node {
    int a, b, c;
    bool operator<(const Node& w) const {
        return c > w.c;
    }
}e[N];
int p[N];

int find(int x) {
    if (p[x] != x) p[x] = find(p[x]);
    return p[x];
}


int main() {
    cin >> n >> m;
    // memset(h, -1, sizeof(int) * (n + 10));
    for (int i = 1; i < m + 1; i++) {
        int a, b, c;
        scanf("%d%d%d", &a, &b, &c);
        e[i] = {a, b, c};
        // add(a, b, c), add(b, a, c);
    }
    sort(e + 1, e + m + 1);
    for (int i = 1; i < n + 1 ; i++) p[i] = i;
    for (int i = 1; i < m + 1; i++) {
        int a = find(e[i].a), b = find(e[i].b);
        if (a != b) {
            res += e[i].c << 1;
            p[a] = find(b);
        }
    }
    printf("%lld\n", res);
    return 0;
}