## implementation

#include <cstdio>
#include <vector>
#include <map>
#include <functional>
#include <cmath>
#include <cassert>
#define repeat(i,n) for (int i = 0; (i) < (n); ++(i))
#define repeat_reverse(i,n) for (int i = (n)-1; (i) >= 0; --(i))
typedef long long ll;
using namespace std;

struct heavy_light_decomposition_t {
int n; // |V'|
vector<int> a; // V ->> V' epic
vector<vector<int> > path; // V' -> V*, bottom to top order, disjoint union of codomain matchs V
vector<map<int,int> > pfind; // V' * V -> int, find in path
vector<int> parent; // V' -> V
heavy_light_decomposition_t(int v, vector<vector<int> > const & g) {
n = 0;
a.resize(g.size());
dfs(v, -1, g);
}
int dfs(int v, int p, vector<vector<int> > const & g) {
int heavy_node = -1;
int heavy_size = 0;
int desc_size = 1;
for (int w : g[v]) if (w != p) {
int size = dfs(w, v, g);
desc_size += size;
if (heavy_size < size) {
heavy_node = w;
heavy_size = size;
}
}
if (heavy_node == -1) {
a[v] = n;
n += 1;
path.emplace_back();
path.back().push_back(v);
pfind.emplace_back();
pfind.back()[v] = 0;
parent.push_back(p);
} else {
int i = a[heavy_node];
a[v] = i;
pfind[i][v] = path[i].size();
path[i].push_back(v);
parent[i] = p;
}
return desc_size;
}
};

struct lowest_common_ancestor_t {
vector<vector<int> > a;
vector<int> depth;
lowest_common_ancestor_t(int v, vector<vector<int> > const & g) {
int n = g.size();
int l = 1 + floor(log2(n));
a.resize(l);
repeat (k,l) a[k].resize(n, -1);
depth.resize(n);
dfs(v, -1, 0, g, a[0], depth);
repeat (k,l-1) {
repeat (i,n) {
if (a[k][i] != -1) {
a[k+1][i] = a[k][a[k][i]];
}
}
}
}
static void dfs(int v, int p, int current_depth, vector<vector<int> > const & g, vector<int> & parent, vector<int> & depth) {
parent[v] = p;
depth[v] = current_depth;
for (int w : g[v]) if (w != p) {
dfs(w, v, current_depth + 1, g, parent, depth);
}
}
// find lca of x, y
int operator () (int x, int y) const { // O(log N)
int l = a.size();
if (depth[x] < depth[y]) swap(x,y);
repeat_reverse (k,l) {
if (a[k][x] != -1 and depth[a[k][x]] >= depth[y]) {
x = a[k][x];
}
}
assert (depth[x] == depth[y]);
assert (x != -1);
if (x == y) return x;
repeat_reverse (k,l) {
if (a[k][x] != a[k][y]) {
x = a[k][x];
y = a[k][y];
}
}
assert (x != y);
assert (a[0][x] == a[0][y]);
return a[0][x];
}
// find the descendant of x for y
int descendant (int x, int y) const {
assert (depth[x] < depth[y]);
int l = a.size();
repeat_reverse (k,l) {
if (a[k][y] != -1 and depth[a[k][y]] >= depth[x]+1) {
y = a[k][y];
}
}
assert (a[0][y] == x);
return y;
}
};

struct segment_tree {
int n;
vector<ll> a, b;
explicit segment_tree(int a_n) {
n = pow(2,ceil(log2(a_n)));
a.resize(2*n-1); // fill 0, unit of add
b.resize(2*n-1); // fill 0, unit of sum
}
void range_add(int l, int r, int z) {
range_add(0, 0, n, l, r, z);
}
void range_add(int i, int il, int ir, int l, int r, int z) {
if (l <= il and ir <= r) {
a[i] += z;
b[i] += z * (ir - il);
} else if (ir <= l or r <= il) {
// nop
} else {
range_add(2*i+1, il, (il+ir)/2, l, r, z);
range_add(2*i+2, (il+ir)/2, ir, l, r, z);
b[i] = a[i] * (ir - il) + b[2*i+1] + b[2*i+2];
}
}
ll range_sum(int l, int r) {
return range_sum(0, 0, n, l, r);
}
ll range_sum(int i, int il, int ir, int l, int r) {
if (l <= il and ir <= r) {
return b[i];
} else if (ir <= l or r <= il) {
return 0; // unit
} else {
return a[i] * (min(ir,r) - max(il,l))
+ range_sum(2*i+1, il, (il+ir)/2, l, r)
+ range_sum(2*i+2, (il+ir)/2, ir, l, r);
}
}
};

ll path_sum(heavy_light_decomposition_t & hl, vector<segment_tree> & sts, int v, int w) {
ll acc = 0;
int i = hl.a[v];
if (hl.a[w] == i) {
assert (hl.pfind[i][v] <= hl.pfind[i][w]); // v must be a descendant of w
acc += sts[i].range_sum(hl.pfind[i][v], hl.pfind[i][w]+1);
} else {
acc += sts[i].range_sum(hl.pfind[i][v], hl.path[i].size());
acc += path_sum(hl, sts, hl.parent[i], w);
}
return acc;
}

ll path_sum(heavy_light_decomposition_t & hl, lowest_common_ancestor_t & lca, vector<segment_tree> & sts, int x, int y) {
int z = lca(x, y);
ll acc = 0;
if (x != z) acc += path_sum(hl, sts, x, lca.descendant(z, x));
if (y != z) acc += path_sum(hl, sts, y, lca.descendant(z, y));
acc += path_sum(hl, sts, z, z);
return acc;
}

void path_add(heavy_light_decomposition_t & hl, vector<segment_tree> & sts, int v, int w, int delta) {
int i = hl.a[v];
if (hl.a[w] == i) {
assert (hl.pfind[i][v] <= hl.pfind[i][w]); // v must be a descendant of w
} else {
}
}

void path_add(heavy_light_decomposition_t & hl, lowest_common_ancestor_t & lca, vector<segment_tree> & sts, int x, int y, int delta) {
int z = lca(x, y);
if (x != z) path_add(hl, sts, x, lca.descendant(z, x), delta);
if (y != z) path_add(hl, sts, y, lca.descendant(z, y), delta);
}

int main() {
// input
int n; scanf("%d", &n);
vector<vector<int> > g(n);
repeat (i,n-1) {
int a, b; scanf("%d%d", &a, &b);
-- a; -- b;
g[a].push_back(b);
g[b].push_back(a);
}
// prepare
const int root = 0;
heavy_light_decomposition_t hl(root, g);
vector<segment_tree> sts;
repeat (i,hl.n) {
sts.emplace_back(hl.path[i].size());
}
repeat (i,n) {
int l = hl.a[i];
}
lowest_common_ancestor_t lca(root, g);
// run
ll ans = 0;
int q; scanf("%d", &q);
repeat (i,q) {
int a, b; scanf("%d%d", &a, &b);
-- a; -- b;
ans += path_sum(hl, lca, sts, a, b);
path_add(hl, lca, sts, a, b, 1);
}
// output
printf("%lld\n", ans);
return 0;
}