#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
#include<string>
#include<map>
#include<iostream>
#include<queue>
using namespace std;
#define isNum(a) (a>='0'&&a<='9')
#define SP putchar(' ')
#define EL putchar('\n')
#define File(a) freopen(a".in","r",stdin),freopen(a".out","w",stdout)
template<class T1>void read(T1 &r_e_a_d);
template<class T1>void write(T1 w_r_i_t_e);
const int N=50005;
int n,m,len=1,x,y,z,a[N],head[N],idn[N],idw[N];
struct EDGE{
int to,next,id;
}edge[N<<1];