g.cpp

#include <cstdio>
#include <vector>
#include <algorithm>
#include <cstring>
using namespace std;

#define NN 200024

int n, root;
vector< pair<int, int> > adj[NN];
int dp[NN];
int ans;

int dfs(int u) {
	dp[u] = 0;
	for(int i = 0; i < (int)adj[u].size(); i++) {
		int j = adj[u][i].first;
		if(dp[j] == -1)
			dp[u] += max(0, adj[u][i].second + dfs(j));
	}
	ans = max(ans, dp[u]);
	return dp[u];
}

int main(void) {
	while(scanf("%d", &n) && n) {
		for(int i = 0; i < NN; i++) adj[i].clear();

		for(int i = 0; i < n; i++) {
			int a, b, p;
			scanf("%d %d %d", &a, &b, &p), a--, b--;
			root = a;
			adj[a].push_back(make_pair(b,p));
			adj[b].push_back(make_pair(a,p));
			root = a;
		}

		ans = 0;
		memset(dp, -1, sizeof(dp));
		dfs(root);
		printf("%d\n", ans);
	}

	return 0;
}