import sys # sys.setrecursionlimit(1000005) int1 = lambda x: int(x)-1 pDB = lambda *x: print(*x, end="\n", file=sys.stderr) p2D = lambda x: print(*x, sep="\n", end="\n\n", file=sys.stderr) def II(): return int(sys.stdin.readline()) def LI(): return list(map(int, sys.stdin.readline().split())) def LLI(rows_number): return [LI() for _ in range(rows_number)] def LI1(): return list(map(int1, sys.stdin.readline().split())) def LLI1(rows_number): return [LI1() for _ in range(rows_number)] def SI(): return sys.stdin.readline().rstrip() # dij = [(0, 1), (-1, 0), (0, -1), (1, 0)] # dij = [(0, 1), (-1, 0), (0, -1), (1, 0), (1, 1), (1, -1), (-1, 1), (-1, -1)] inf = (1 << 63)-1 # inf = (1 << 31)-1 md = 10**9+7 # md = 998244353 class LCA: def __init__(self, parents, depth): self.n = len(parents) self.parents = parents self.depth = depth self.max_level = max(self.depth).bit_length() self.ancestor = [self.parents]+[[-1]*self.n for _ in range(self.max_level)] row0 = self.ancestor[0] for lv in range(self.max_level): row1 = self.ancestor[lv+1] for u in range(self.n): if row0[u] == -1: continue row1[u] = row0[row0[u]] row0 = row1 def anc(self, u, v): diff = self.depth[u]-self.depth[v] if diff < 0: u, v = v, u diff = abs(diff) u = self.up(u, diff) if u == v: return u for lv in range(self.depth[u].bit_length()-1, -1, -1): anclv = self.ancestor[lv] if anclv[u] != anclv[v]: u, v = anclv[u], anclv[v] return self.parents[u] def up(self, u, dist): lv = 0 while dist and u != -1: if dist & 1: u = self.ancestor[lv][u] lv, dist = lv+1, dist >> 1 return u n=II() to=[[] for _ in range(n)] for _ in range(n-1): u,v=LI1() to[u].append(v) to[v].append(u) parent, depth, vis = [-1]*n, [0]*n, [0]*n def dfs(root): uu = [] vis[root] = 1 stack = [root] while stack: iu = stack.pop() i, u = divmod(iu, n) if i == 0: uu.append(u) # care to's format while i < len(to[u]) and vis[to[u][i]]: i += 1 if i < len(to[u]): stack.append((i+1)*n+u) # care to's format v = to[u][i] vis[v] = 1 stack.append(v) parent[v] = u depth[v] = depth[u]+1 return uu uu=dfs(0) lca=LCA(parent,depth) dp=[0]*(n+1) for _ in range(II()): u,v=LI1() a=lca.anc(u,v) dp[u]+=1 dp[v]+=1 dp[a]-=1 dp[parent[a]]-=1 for u in uu[::-1]: v=parent[u] dp[v]+=dp[u] ans=0 for c in dp[:-1]: ans+=c*(c+1)//2 print(ans)