毒瘤define版DSU

#include <iostream>
#include <algorithm>
//#define anc(x) (pa[x]=pa[pa[x]]=pa[pa[pa[x]]]=pa[pa[pa[pa[x]]]]=pa[pa[pa[pa[pa[x]]]]]=pa[pa[pa[pa[pa[pa[x]]]]]]=pa[pa[pa[pa[pa[pa[pa[x]]]]]]])
#define anc(x) (x==pa[x] ? x : (pa[x]==pa[pa[x]] ? pa[x] : (pa[pa[x]]==pa[pa[pa[x]]] ? pa[pa[x]] : (pa[pa[pa[x]]]==pa[pa[pa[pa[x]]]] ? pa[pa[pa[x]]] : (pa[pa[pa[pa[x]]]]==pa[pa[pa[pa[pa[x]]]]] ? pa[pa[pa[pa[x]]]] : (pa[pa[pa[pa[pa[x]]]]]==pa[pa[pa[pa[pa[pa[x]]]]]] ? pa[pa[pa[pa[pa[x]]]]] : (pa[pa[pa[pa[pa[pa[x]]]]]]==pa[pa[pa[pa[pa[pa[pa[x]]]]]]] ? pa[pa[pa[pa[pa[pa[x]]]]]] : (pa[pa[pa[pa[pa[pa[pa[x]]]]]]]==pa[pa[pa[pa[pa[pa[pa[pa[x]]]]]]]] ? pa[pa[pa[pa[pa[pa[pa[x]]]]]]] : pa[pa[pa[pa[pa[pa[pa[pa[x]]]]]]]]))))))))
#define join(x,y) ((x=anc(x))!=(y=anc(y)) && (rk[x]<rk[y]&&(x^=y^=x^=y),pa[y]=x,rk[x]!=rk[y]||++rk[x]))

using namespace std;
typedef unsigned ll;
constexpr ll N = 12525, M = 1252525;

struct edge{ll u,v,w;} E[M];
bool operator<(const edge& a, const edge& b){return a.w<b.w;}
ll pa[N],rk[N],n,m,sum,CC;
/*#include <string>
void show(string x, int d){
    for(int i = 0; i < d; i++) {
        cout << '(' << x << "==pa[" << x << "] ? " << x << " : ";
        x = "pa["+x+"]";
        if(i==d-1) cout << x;
    }
    for(int i = 0; i < d; i++) cout << ')';
}*/
signed main(){
    //show("x",8);
    //return 0;
    ios_base::sync_with_stdio(0), cin.tie(0);
    while(cin >> n >> m, n||m){
        for(int i = 1; i <= n; i++) pa[i]=i, rk[i]=0;
        for(int i = 0; i < m; i++) cin >> E[i].u >> E[i].v >> E[i].w;
        sort(E,E+m);
        sum = 0, CC = n;
        for(int i = 0; i < m; i++) if(join(E[i].u,E[i].v)) sum += E[i].w, CC--;
        if(CC == 1)
            cout << sum << '\n';
        else
            cout << -1 << '\n';
    }
}