/*普利姆*/
# include <iostream>
# include <algorithm>
# include <stdio.h>
# include <vector>
# include <string.h>
# define MAXN 3005
# define INFI 9999999
using namespace std;
typedef struct Node
{
int v;
int len;
}Node;
int n,m,sum=0;
vector<Node > vt[MAXN];
int lowcost[MAXN];
int vis[MAXN];
void Prim(int x)
{
for(int i=1; i<=n;++i)
{
lowcost[i] = INFI;
}
for(int i=0; i<vt[x].size(); ++i)
{
lowcost[vt[x][i].v] = vt[x][i].len;
}
lowcost[1] = 0