就这个Kruskal爽！！！

#include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>
using namespace std;
struct node2{
	int x, y, len;
	bool operator < (const node2 &b) const{
		return len < b.len;
	}
}edges[200005];
int father[5005]; 
int n, m, x, y, z;
int find(int idx){
	if(idx != father[idx]) idx = find(father[idx]);
	return father[idx];
}
bool merge(int x, int y){
	int p = find(x), q = find(y);
	if(p == q) return 0;
	father[max(p, q)] = min(p, q);
	return 1;
}
int kruskal(){
	sort(edges + 1, edges + m + 1);
	int ct = 0, ctt = 0;
	for(int i = 1; i <= n; i++) father[i] = i;
	for(int i = 1; i <= m; i++){
		if(merge(edges[i].x, edges[i].y)){
			ct += edges[i].len, ctt++;
			if(ctt >= n - 1) return ct;
		}
	}
	return -1;
}
int read(){
	char c = getchar();
	int x = 0, f = 1;
	while(!isdigit(c)){
		if(c == '-') f = -f;
		c = getchar();
	}
	while(isdigit(c)){
		x = (x << 3) + (x << 1) + c - '0';
		c = getchar();
	}
	return x * f;
}
int main(){
	n = read(), m = read();
	for(int i = 1; i <= m; i++){
		x = read(), y = read(), z = read();
		edges[i] = {x, y, z};
	}
	int ans = kruskal();
	if(ans == -1) cout << "orz";
	else cout << ans;

	return 0;
}