HDU6446

#include<bits/stdc++.h>

using namespace std;

#define gc c=getchar()
#define r(x) read(x)
#define ll long long

template<typename T>
inline void read(T&x){
    x=0;T k=1;char gc;
    while(!isdigit(c)){if(c=='-')k=-1;gc;}
    while(isdigit(c)){x=x*10+c-'0';gc;}x*=k;
}

const int N=1e5+7;
const int p=1e9+7;

int n,ecnt;
int fir[N];
int w[N<<1];
int to[N<<1];
int nex[N<<1];

inline void addedge(int u,int v,int c){
    nex[++ecnt]=fir[u],fir[u]=ecnt,to[ecnt]=v,w[ecnt]=c;
    nex[++ecnt]=fir[v],fir[v]=ecnt,to[ecnt]=u,w[ecnt]=c;
}

ll ans;

int dfs(int x,int f,int c){
    int siz=1;
    for(int i=fir[x];i;i=nex[i]){
        int v=to[i];
        if(v==f)continue;
        siz+=dfs(v,x,w[i]);
    }
    ans+=(ll)(n-siz)*siz%p*c%p;
    return siz;
}

int main(){
    while(~scanf("%d",&n)){
        ans=ecnt=0;
        memset(fir+1,0,sizeof(fir));
        for(int i=1;i<n;++i){
            int u,v,c;
            r(u),r(v);r(c);
            addedge(u,v,c);
        }
        dfs(1,0,0);
        ans=ans*2%p;
        for(int i=2;i<n;++i){
            (ans*=i)%=p;
        }
        printf("%lld\n",ans);
    }
}