#include <iostream>
#include <cstdio>
#define ls t[p].l
#define rs t[p].r
using namespace std;

typedef long long LL;

const int N = 500005, P = 998244353;

int n, m, dep[N], L, g[N], rt[N], w1, w2;

int head[N], numE = 1;

struct E{
	int next, v;
} e[N << 1];

void inline add(int u, int v) {
	e[++numE] = (E) { head[u], v };
	head[u] = numE;
}

void dfs(int u, int fa) {
	L = max(L, dep[u]);
	for (int i = head[u]; i; i = e[i].next) {
		int v = e[i].v;
		if (v == fa) continue;
		dep[v] = dep[u] + 1;
		dfs(v, u);
	}
}

int idx;

struct T{
	int l, r, sum, tag;
} t[N * 20];

void inline pushdown(int p) {
	if (t[p].tag != 1) {
		t[ls].sum = (LL)t[ls].sum * t[p].tag % P;
		t[rs].sum = (LL)t[rs].sum * t[p].tag % P;
		t[ls].tag = (LL)t[ls].tag * t[p].tag % P;
		t[rs].tag = (LL)t[rs].tag * t[p].tag % P;
		t[p].tag = 1;
	}
}

void inline pushup(int p) {
	t[p].sum = (t[ls].sum + t[rs].sum) % P;
}

void build(int &p, int l, int r, int x) {
	t[p = ++idx].tag = 1;
	if (l == r) { t[p].sum = 1; return; } 
	int mid = (l + r) >> 1;
	if (x <= mid) build(t[p].l, l, mid, x);
	else build(t[p].r, mid + 1, r, x);
	pushup(p);
}

int query(int p, int l, int r, int x, int y) {
	if (!p) return 0;
	if (x <= l && r <= y) return t[p].sum;
	pushdown(p);
	int mid = (l + r) >> 1, res = 0;
	if (x <= mid) (res += query(t[p].l, l, mid, x, y)) %= P;
	if (mid < y) (res += query(t[p].r, mid + 1, r, x, y)) %= P;
	return res;
}

void merge(int &p, int q, int l, int r) {
	if (!p && !q) return;
	if (!p) {
		p = q; (w1 += t[p].sum) %= P;
		t[p].sum = (LL)t[p].sum * w2 % P;
		t[p].tag = (LL)t[p].tag * w2 % P;
		return;
	}
	if (!q) {
		(w2 += t[p].sum) %= P;
		t[p].sum = (LL)t[p].sum * w1 % P;
		t[p].tag = (LL)t[p].tag * w1 % P;
		return;
	}
	if (l == r) {
		int x = t[q].sum, y = t[p].sum;
		(w1 += x) %= P;
		t[p].sum = ((LL)y * w1 + (LL)x * w2) % P;
		(w2 += y) %= P;
		return;
	}
	pushdown(p); pushdown(q);
	int mid = (l + r) >> 1;
	merge(t[p].l, t[q].l, l, mid);
	merge(t[p].r, t[q].r, mid + 1, r);
	pushup(p);
}

void dfs2(int u, int fa) {
	for (int i = head[u]; i; i = e[i].next) {
		int v = e[i].v;
		if (v == fa) continue;
		dfs2(v, u);
		w1 = query(rt[v], 0, L, 0, dep[u]), w2 = 0; 
		merge(rt[u], rt[v], 0, L);
	}
}

int main() {
	//freopen("destiny.in", "r", stdin);
	//freopen("destiny.out", "w", stdout);
	scanf("%d", &n);
	for (int i = 1, u, v; i < n; i++)
		scanf("%d%d", &u, &v), add(u, v), add(v, u);
	dep[1] = 1; dfs(1, 0);
	scanf("%d", &m);
	for (int i = 1, u, v; i <= m; i++) {
		scanf("%d%d", &u, &v);
		g[v] = max(g[v], dep[u]);
	}
	for (int i = 1; i <= n; i++) build(rt[i], 0, L, g[i]);
	dfs2(1, 0);
	printf("%d\n", query(rt[1], 0, L, 0, 0));
	return 0;
}