#include <cstdio>
#include <queue>
using namespace std;
const int N = 1000 + 10;
int p, G[N][2], s;
bool l[N];
void DFS(int u, int d) {
    for(int i=0; i<2; i++)
        if(G[u][i]) {
            if(!l[G[u][i]]) {
                l[G[u][i]] = 1;
                DFS(G[u][i], d+1);
                l[G[u][i]] = 0;
            }
        } else s = max(s, d);
}
int main() {
    freopen("stroll.in", "r", stdin);
    freopen("stroll.out", "w", stdout);
    scanf("%d", &p);
    int u, v, w;
    for(int i=1; i<p; i++) {
        scanf("%d %d %d", &w, &u, &v);
        G[w][0] = u, G[w][1] = v;
    }
    DFS(1, 1);
    printf("%d\n", s);
    return 0;
}