#pragma GCC optimize ("Ofast")
#include<bits/stdc++.h>
using namespace std;
void *wmem;
char memarr[96000000];
template<class S, class T> inline S max_L(S a,T b){
  return a>=b?a:b;
}
template<class T> inline void walloc1d(T **arr, int x, void **mem = &wmem){
  static int skip[16] = {0, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1};
  (*mem) = (void*)( ((char*)(*mem)) + skip[((unsigned long long)(*mem)) & 15] );
  (*arr)=(T*)(*mem);
  (*mem)=((*arr)+x);
}
inline int my_getchar_unlocked(){
  static char buf[1048576];
  static int s = 1048576;
  static int e = 1048576;
  if(s == e && e == 1048576){
    e = fread_unlocked(buf, 1, 1048576, stdin);
    s = 0;
  }
  if(s == e){
    return EOF;
  }
  return buf[s++];
}
inline void rd(int &x){
  int k;
  int m=0;
  x=0;
  for(;;){
    k = my_getchar_unlocked();
    if(k=='-'){
      m=1;
      break;
    }
    if('0'<=k&&k<='9'){
      x=k-'0';
      break;
    }
  }
  for(;;){
    k = my_getchar_unlocked();
    if(k<'0'||k>'9'){
      break;
    }
    x=x*10+k-'0';
  }
  if(m){
    x=-x;
  }
}
struct MY_WRITER{
  char buf[1048576];
  int s;
  int e;
  MY_WRITER(){
    s = 0;
    e = 1048576;
  }
  ~MY_WRITER(){
    if(s){
      fwrite_unlocked(buf, 1, s, stdout);
    }
  }
}
;
MY_WRITER MY_WRITER_VAR;
void my_putchar_unlocked(int a){
  if(MY_WRITER_VAR.s == MY_WRITER_VAR.e){
    fwrite_unlocked(MY_WRITER_VAR.buf, 1, MY_WRITER_VAR.s, stdout);
    MY_WRITER_VAR.s = 0;
  }
  MY_WRITER_VAR.buf[MY_WRITER_VAR.s++] = a;
}
inline void wt_L(char a){
  my_putchar_unlocked(a);
}
inline void wt_L(int x){
  int s=0;
  int m=0;
  char f[10];
  if(x<0){
    m=1;
    x=-x;
  }
  while(x){
    f[s++]=x%10;
    x/=10;
  }
  if(!s){
    f[s++]=0;
  }
  if(m){
    my_putchar_unlocked('-');
  }
  while(s--){
    my_putchar_unlocked(f[s]+'0');
  }
}
inline void wt_L(unsigned x){
  int s=0;
  char f[10];
  while(x){
    f[s++]=x%10;
    x/=10;
  }
  if(!s){
    f[s++]=0;
  }
  while(s--){
    my_putchar_unlocked(f[s]+'0');
  }
}
inline void wt_L(long long x){
  int s=0;
  int m=0;
  char f[20];
  if(x<0){
    m=1;
    x=-x;
  }
  while(x){
    f[s++]=x%10;
    x/=10;
  }
  if(!s){
    f[s++]=0;
  }
  if(m){
    my_putchar_unlocked('-');
  }
  while(s--){
    my_putchar_unlocked(f[s]+'0');
  }
}
inline void wt_L(unsigned long long x){
  int s=0;
  char f[21];
  while(x){
    f[s++]=x%10;
    x/=10;
  }
  if(!s){
    f[s++]=0;
  }
  while(s--){
    my_putchar_unlocked(f[s]+'0');
  }
}
int WRITER_DOUBLE_DIGIT = 15;
inline int writerDigit_double(){
  return WRITER_DOUBLE_DIGIT;
}
inline void writerDigit_double(int d){
  WRITER_DOUBLE_DIGIT = d;
}
inline void wt_L(double x){
  const int d = WRITER_DOUBLE_DIGIT;
  int k;
  int r;
  double v;
  if(x!=x || (x==x+1 && x==2*x)){
    my_putchar_unlocked('E');
    my_putchar_unlocked('r');
    my_putchar_unlocked('r');
    return;
  }
  if(x < 0){
    my_putchar_unlocked('-');
    x = -x;
  }
  x += 0.5 * pow(0.1, d);
  r = 0;
  v = 1;
  while(x >= 10*v){
    v *= 10;
    r++;
  }
  while(r >= 0){
    r--;
    k = floor(x / v);
    if(k >= 10){
      k = 9;
    }
    if(k <= -1){
      k = 0;
    }
    x -= k * v;
    v *= 0.1;
    my_putchar_unlocked(k + '0');
  }
  if(d > 0){
    my_putchar_unlocked('.');
    v = 1;
    for(r=(0);r<(d);r++){
      v *= 0.1;
      k = floor(x / v);
      if(k >= 10){
        k = 9;
      }
      if(k <= -1){
        k = 0;
      }
      x -= k * v;
      my_putchar_unlocked(k + '0');
    }
  }
}
inline void wt_L(const char c[]){
  int i=0;
  for(i=0;c[i]!='\0';i++){
    my_putchar_unlocked(c[i]);
  }
}
inline void wt_L(string &x){
  int i=0;
  for(i=0;x[i]!='\0';i++){
    my_putchar_unlocked(x[i]);
  }
}
struct graph{
  int N;
  int *es;
  int **edge;
  void setEdgeRootedTree(int N__, int M, int A[], int B[], int root=0, int reorder=0, int cnv[] = NULL, void **mem = &wmem){
    int i;
    int j;
    int k;
    int *dist;
    int *q;
    int qs;
    int qe;
    int *ind;
    void *tmem;
    N = N__;
    tmem = ((char*)(*mem)) + (sizeof(int) * N + 15) + (sizeof(int*) * N + 15) + (sizeof(int) * M + 15 * N);
    walloc1d(&es, N, mem);
    walloc1d(&edge, N, mem);
    for(i=(0);i<(N);i++){
      es[i] = 0;
    }
    for(i=(0);i<(M);i++){
      es[A[i]]++;
      es[B[i]]++;
    }
    for(i=(0);i<(N);i++){
      walloc1d(&edge[i], es[i], &tmem);
    }
    for(i=(0);i<(N);i++){
      es[i] = 0;
    }
    for(i=(0);i<(M);i++){
      edge[A[i]][es[A[i]]++] = B[i];
      edge[B[i]][es[B[i]]++] = A[i];
    }
    walloc1d(&dist, N, &tmem);
    walloc1d(&q, N, &tmem);
    walloc1d(&ind, N, &tmem);
    if(cnv==NULL){
      walloc1d(&cnv, N, &tmem);
    }
    for(i=(0);i<(N);i++){
      dist[i] = -1;
    }
    dist[root] = 0;
    qs = qe = 0;
    q[qe++] = root;
    while(qs < qe){
      i = q[qs++];
      for(j=(0);j<(es[i]);j++){
        k = edge[i][j];
        if(dist[k]==-1){
          dist[k] = dist[i] + 1;
          q[qe++] = k;
        }
      }
    }
    if(reorder == 0){
      for(i=(0);i<(N);i++){
        cnv[i] = i;
      }
      for(i=(0);i<(N);i++){
        ind[i] = i;
      }
    }
    else{
      for(i=(0);i<(N);i++){
        cnv[i] = q[i];
      }
      for(i=(0);i<(N);i++){
        ind[cnv[i]] = i;
      }
    }
    for(i=(0);i<(N);i++){
      es[i] = 0;
    }
    for(i=(0);i<(M);i++){
      j = A[i];
      k = B[i];
      if(dist[j] > dist[k]){
        swap(j, k);
      }
      es[ind[j]]++;
    }
    for(i=(0);i<(N);i++){
      walloc1d(&edge[i], es[i], mem);
    }
    for(i=(0);i<(N);i++){
      es[i] = 0;
    }
    for(i=(0);i<(M);i++){
      j = A[i];
      k = B[i];
      if(dist[j] > dist[k]){
        swap(j, k);
      }
      j = ind[j];
      k = ind[k];
      edge[j][es[j]++] = k;
    }
  }
  int preorder(int res[], int root = 0, void *mem=wmem){
    int i;
    int j;
    int k;
    int sts;
    int sz = 0;
    long long *st;
    char *vis;
    walloc1d(&vis, N, &mem);
    walloc1d(&st, N, &mem);
    sts = 0;
    st[sts++] = ((long long)root) << 32;
    for(i=(0);i<(N);i++){
      vis[i] = 0;
    }
    vis[root] = 1;
    while(sts){
      i = st[--sts] >> 32;
      j = st[sts] & 2147483647;
      if(j==0){
        res[sz++] = i;
      }
      while(j < es[i]){
        k = edge[i][j++];
        if(vis[k]){
          continue;
        }
        if(j < es[i]){
          st[sts++] = (((long long)i) << 32) + j;
        }
        vis[k] = 1;
        st[sts++] = ((long long)k) << 32;
        break;
      }
    }
    return sz;
  }
}
;
int N;
int A[100000];
int B[100000];
int U[100000];
int V[100000];
long long dp[2][100000];
graph g;
int pre[100000];
int main(){
  int t_ynMSdg;
  wmem = memarr;
  rd(N);
  {
    int Lj4PdHRW;
    for(Lj4PdHRW=(0);Lj4PdHRW<(N);Lj4PdHRW++){
      rd(A[Lj4PdHRW]);
    }
  }
  {
    int e98WHCEY;
    for(e98WHCEY=(0);e98WHCEY<(N);e98WHCEY++){
      rd(B[e98WHCEY]);
    }
  }
  {
    int FmcKpFmN;
    for(FmcKpFmN=(0);FmcKpFmN<(N-1);FmcKpFmN++){
      rd(U[FmcKpFmN]);U[FmcKpFmN] += (-1);
      rd(V[FmcKpFmN]);V[FmcKpFmN] += (-1);
    }
  }
  g.setEdgeRootedTree(N,N-1,U,V);
  g.preorder(pre);
  for(t_ynMSdg=(N)-1;t_ynMSdg>=(0);t_ynMSdg--){
    int tU__gIr_;
    auto &i = pre[t_ynMSdg];
    dp[0][i] = 0;
    dp[1][i] = A[i];
    for(tU__gIr_=(0);tU__gIr_<(g.es[i]);tU__gIr_++){
      auto &j = g.edge[i][tU__gIr_];
      dp[0][i] +=max_L(dp[0][j]+B[i]+B[j], dp[1][j]);
      dp[1][i] +=max_L(dp[0][j], dp[1][j]);
    }
  }
  wt_L(max_L(dp[0][0], dp[1][0]));
  wt_L('\n');
  return 0;
}
// cLay varsion 20200813-1 [beta]

// --- original code ---
// int N, A[1d5], B[1d5], U[1d5], V[1d5];
// ll dp[2][1d5];
// graph g;
// int pre[1d5];
// {
//   rd(N,A(N),B(N),(U--,V--)(N-1));
//   g.setEdgeRootedTree(N,N-1,U,V);
//   g.preorder(pre);
// 
//   rrep[pre](i,N){
//     dp[0][i] = 0;
//     dp[1][i] = A[i];
//     rep[g.edge[i]](j,g.es[i]){
//       dp[0][i] += max(dp[0][j]+B[i]+B[j], dp[1][j]);
//       dp[1][i] += max(dp[0][j], dp[1][j]);
//     }
//   }
//   wt(max(dp[0][0],dp[1][0]));
// }