#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int M = 2e5 + 5;
const ll mod = 1e9 + 7;
ll  n,z,res;
int f[M][2],siz[M][2];
int  find(int x,int y){
    if(!f[x][y])return x;
    return f[x][y]=find(f[x][y],y);
}
int main()
{
	freopen("0-1-Tree.in","r",stdin);
	freopen("0-1-Tree.out","w",stdout); 
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    cin>>n;
    for(int i=1;i<=n-1;i++){
        int x,y,z;cin>>x>>y>>z;
        int fx=find(x,z);
        int fy=find(y,z);
        if(fx!=fy){
            f[fx][z]=fy;
        }
    }
    for(int i=1;i<=n;i++){
        siz[find(i,0)][0]++;
        siz[find(i,1)][1]++;
    }
    for(int i=1;i<=n;i++){
        res+=1ll* siz[find(i,1)][1]*siz[find(i,0)][0]-1;
    }
    cout<<res<<endl;
    return 0;
}