void dfs3(int node, int pa)
{
for (int e = nrbegin[node]; e; e = nrnext[e]) {
int son = nrto[e];
if (son == pa)
continue;
int sans = 0;
if (max2[node][0].first != son)
sans = std::max(sans, max2[node][0].second);
else
sans = std::max(sans, max2[node][1].second);
sans += dp1[node] - std::max(0, dp0[son] - 2 * cost[nredge[e]]);
int sbns = dp3[node] + dp0[node] - std::max(0, dp0[son] - 2 * cost[nredge[e]]);
dp3[son] = std::max(0, std::max(sans, sbns) - cost[nredge[e]]);
dfs3(son, node);
}
}
void dfs3(int u,int fas,int deps)
{
if (fas==-1)
{
for(int i=0;i<=Bei;i++)
fa[u][i]=u;
sum[u]=we[u];
} else
{
fa[u][0]=fas;
for(int i=1;i<=Bei;i++)
fa[u][i]=fa[ fa[u][i-1] ][i-1];
sum[u]=sum[fas]+we[u];
}
dep[u]=deps;
for(int p=trbox[u];p!=-1;p=tre[p].next)
if (tre[p].to!=fas)
dfs3(tre[p].to,u,deps+1);
}
void prelca()
{
dfs3(0,-1,0);
}
inline void do_dp3()
{
dp3[1] = 0;
dfs3(1, 0);
}