#include <bits/stdc++.h>
#define For(a, b, c) for (int a = b; a <= c; ++a)
#define Dor(a, b, c) for (int a = b; a >= c; --a)
using namespace std;
const int N = 500007, M = 40000000, P = 998244353;
int n, m, t, hd[N], nt[N << 1], to[N << 1], D[N], T[N], rt[N], ls[M], rs[M], F[M], G[M];
void walk(int u, int f = 0) {
    D[u] = D[f] + 1;
    for (int e = hd[u]; e; e = nt[e]) {
        int v = to[e];
        if (v == f)
            continue;
        walk(v, u);
    }
}
int E(int u) { return !ls[u] && !rs[u]; }
void dn(int u) {
    if (G[u] == 1 && !F[u])
        return;
    int &l = ls[u], &r = rs[u];
    if (!l)
        l = ++t, F[l] = 1;
    if (!r)
        r = ++t, F[r] = 1;
    G[l] = 1LL * G[l] * G[u] % P, F[l] = (1LL * G[u] * F[l] + F[u]) % P;
    G[r] = 1LL * G[r] * G[u] % P, F[r] = (1LL * G[u] * F[r] + F[u]) % P;
    G[u] = 1, F[u] = 0;
}
int mrg(int x, int y) {
    if (E(x) || E(y)) {
        if (E(y))
            swap(x, y);
        G[y] = 1LL * F[x] * G[y] % P;
        F[y] = 1LL * F[x] * F[y] % P;
        return y;
    }
    dn(x), dn(y);
    ls[x] = mrg(ls[x], ls[y]);
    rs[x] = mrg(rs[x], rs[y]);
    return x;
}
void clr(int &u, int l, int r, int L = 0, int R = n) {
    if (l == L && r == R) {
        ls[u] = rs[u] = G[u] = F[u] = 0;
        return;
    }
    int M = (L + R) >> 1;
    dn(u);
    if (r <= M)
        clr(ls[u], l, r, L, M);
    else if (l > M)
        clr(rs[u], l, r, M + 1, R);
    else
        clr(ls[u], l, M, L, M), clr(rs[u], M + 1, r, M + 1, R);
}
int qry(int &u, int x, int L = 0, int R = n) {
    if (E(u))
        return F[u];
    int M = (L + R) >> 1;
    dn(u);
    if (x <= M)
        return qry(ls[u], x, L, M);
    return qry(rs[u], x, M + 1, R);
}
void fly(int u, int f = 0) {
    rt[u] = ++t, F[t] = 1;
    for (int e = hd[u]; e; e = nt[e]) {
        int v = to[e];
        if (v == f)
            continue;
        fly(v, u);
        rt[u] = mrg(rt[u], rt[v]);
    }
    int s = qry(rt[u], D[u]);
    if (T[u])
        clr(rt[u], 0, T[u] - 1);
    if (u > 1)
        (F[rt[u]] += s) %= P;
}
int main() {
    scanf("%d", &n);
    int e = 0;
    For(i, 1, n - 1) {
        int x, y;
        scanf("%d%d", &x, &y);
        nt[++e] = hd[x], hd[x] = e, to[e] = y;
        nt[++e] = hd[y], hd[y] = e, to[e] = x;
    }
    walk(1);
    scanf("%d", &m);
    For(i, 1, m) {
        int x, y;
        scanf("%d%d", &x, &y), T[y] = max(T[y], D[x] + 1);
    }
    fly(1);
    int f = qry(rt[1], 0);
    printf("%d", f);
    return 0;
}