func_code_string: #include <bits/stdc++.h>   using namespace std;   long long inf;   const double eps = 1e-8;   const double pi = acos(-1.0);   template <class T>   long long chkmin(T &a, T b) {     return a > b ? a = b, 1 : 0;   }   template <class T>   long long chkmax(T &a, T b) {     return a < b ? a = b, 1 : 0;   }   template <class T>   T sqr(T a) {     return a * a;   }   template <class T>   T mmin(T a, T b) {     return a < b ? a : b;   }   template <class T>   T mmax(T a, T b) {     return a > b ? a : b;   }   template <class T>   T aabs(T a) {     return a < 0 ? -a : a;   }   template <class T>   long long dcmp(T a, T b) {     return a > b;   }   template <long long *a>   long long cmp_a(long long first, long long second) {     return a[first] < a[second];   }   struct __INIT__ {     __INIT__() { memset(&inf, 0x3f, sizeof(inf)); }   } __INIT___;   namespace io {   const long long SIZE = (1 << 21) + 1;   char ibuf[SIZE], *iS, *iT, obuf[SIZE], *oS = obuf, *oT = oS + SIZE - 1, c,                                          qu[55];   long long f, qr;   inline void flush() {     fwrite(obuf, 1, oS - obuf, stdout);     oS = obuf;   }   inline void putc(char first) {     *oS++ = first;     if (oS == oT) flush();   }   template <typename A>   inline bool read(A &first) {     for (f = 1, c = (iS == iT ? (iT = (iS = ibuf) + fread(ibuf, 1, SIZE, stdin),                                 (iS == iT ? EOF : *iS++))                               : *iS++);          c <  0  || c >  9 ;          c = (iS == iT ? (iT = (iS = ibuf) + fread(ibuf, 1, SIZE, stdin),                          (iS == iT ? EOF : *iS++))                        : *iS++))       if (c ==  - )         f = -1;       else if (c == EOF)         return 0;     for (first = 0; c <=  9  && c >=  0 ;          c = (iS == iT ? (iT = (iS = ibuf) + fread(ibuf, 1, SIZE, stdin),                          (iS == iT ? EOF : *iS++))                        : *iS++))       first = first * 10 + (c & 15);     first *= f;     return 1;   }   inline bool read(char &first) {     while ((first = (iS == iT ? (iT = (iS = ibuf) + fread(ibuf, 1, SIZE, stdin),                                  (iS == iT ? EOF : *iS++))                               : *iS++)) ==     ||            first ==   n  || first ==   r )       ;     return first != EOF;   }   inline bool read(char *first) {     while ((*first = (iS == iT ? (iT = (iS = ibuf) + fread(ibuf, 1, SIZE, stdin),                                   (iS == iT ? EOF : *iS++))                                : *iS++)) ==   n  ||            *first ==     || *first ==   r )       ;     if (*first == EOF) return 0;     while (!(*first ==   n  || *first ==     || *first ==   r ))       *(++first) = (iS == iT ? (iT = (iS = ibuf) + fread(ibuf, 1, SIZE, stdin),                                 (iS == iT ? EOF : *iS++))                              : *iS++);     *first = 0;     return 1;   }   template <typename A, typename... B>   inline bool read(A &first, B &...second) {     return read(first) && read(second...);   }   template <typename A>   inline bool write(A first) {     if (!first) putc( 0 );     if (first < 0) putc( - ), first = -first;     while (first) qu[++qr] = first % 10 +  0 , first /= 10;     while (qr) putc(qu[qr--]);     return 0;   }   inline bool write(char first) {     putc(first);     return 0;   }   inline bool write(const char *first) {     while (*first) {       putc(*first);       ++first;     }     return 0;   }   inline bool write(char *first) {     while (*first) {       putc(*first);       ++first;     }     return 0;   }   template <typename A, typename... B>   inline bool write(A first, B... second) {     return write(first) || write(second...);   }   struct Flusher_ {     ~Flusher_() { flush(); }   } io_flusher_;   }  // namespace io   using io ::putc;   using io ::read;   using io ::write;   long long a[3005], b[3005];   vector<long long> to[3005];   pair<long long, long long> f[3005][3005], g[3005];   long long siz[3005];   pair<long long, long long> operator+(pair<long long, long long> a,                                        pair<long long, long long> b) {     return make_pair(a.first + b.first, a.second + b.second);   }   void dfs(long long first, long long fa) {     f[first][0] = make_pair(0, b[first]);     siz[first] = 0;     for (auto i : to[first])       if (i != fa) {         dfs(i, first);         for (long long j = 0; j <= siz[first] + siz[i] + 1; ++j)           g[j] = make_pair(-1, -1);         for (long long j = 0; j <= siz[first]; ++j)           for (long long k = 0; k <= siz[i]; ++k) {             chkmax(g[j + k], f[first][j] + f[i][k]);             chkmax(g[j + k + 1], make_pair(f[first][j].first + f[i][k].first +                                                (f[i][k].second > 0),                                            f[first][j].second));           }         for (long long j = 0; j <= siz[first] + siz[i] + 1; ++j)           f[first][j] = g[j];         siz[first] += siz[i] + 1;       }   }   signed main() {     long long t, n, m, u, v;     read(t);     for (; t; --t) {       read(n, m);       for (long long i = 1; i <= n; ++i) read(a[i]);       for (long long i = 1; i <= n; ++i) {         read(b[i]);         b[i] -= a[i];         to[i].clear();       }       for (long long i = 1; i < n; ++i) {         read(u, v);         to[u].push_back(v);         to[v].push_back(u);       }       dfs(1, 0);       write(f[1][m - 1].first + (f[1][m - 1].second > 0),   n );     }     return 0;   }   