#include <cstdio>
#include <algorithm>
#include <vector>
//FILE *fin = fopen("a.in", "r"), *fout = fopen("a.out", "w");
#define fin stdin
#define fout stdout
#define MAXN 3009
char sir[2][5] = {
{
'N', 'O', '\n', '\0', '\0'
},
{
'Y', 'E', 'S', '\n', '\0'
}
};
int n, k, l, vf, cnt;
bool ans[MAXN];
int G[MAXN], D[MAXN]; /// gauche, droite
int st[MAXN], r[MAXN], h[MAXN], v[MAXN];
std::vector < int > g[MAXN], e[MAXN];
bool cmp(const int &a, const int &b) {
return h[a] < h[b];
}
inline bool check0(int x) { /// nu folosesc niciun symlink
return k == (h[st[vf]] + x);
}
inline bool check1(int x) { /// folosesc un singur symlink
/// conditia e sa existe i, j a.i. : k = l + x + h[st[vf]] - h[st[i]] + h[r[j]], 0 < i <= vf, 0 <= j <= n
/// h[r[j]] = h[st[i]] + k - l - x - h[st[vf]]
int j = 0;
for (int i = 1; i <= vf; i++) {
while (j <= n && h[r[j]] < h[st[i]] + k - l - x - h[st[vf]])
j++;
if (j <= n && h[r[j]] == h[st[i]] + k - l - x - h[st[vf]])
return 1;
}
return 0;
}
inline bool stramos(int x, int y) { /// este x stramos al lui y?
return G[x] <= G[y] && D[y] <= D[x];
}
inline bool solve(int x) {
/// 0 <= i <= n, 0 < j <= vf, r[i] e in subarborele lui st[j], a.i. : x = l + h[r[i]] - h[st[j]]
/// h[st[j]] = h[r[i]] + l - x
int j = 1;
for (int i = 0; i <= n; i++) {
while (j <= vf && h[st[j]] < h[r[i]] + l - x)
j++;
if (j <= vf && h[st[j]] == h[r[i]] + l - x && stramos(st[j], r[i]))
return 1;
}
return 0;
}
inline bool check2(int x) { /// folosesc mai multe symlinkuri
/// conditia e sa existe i, j a.i. : (l + h[r[i]] - h[st[j]]) divide (k - x - h[st[vf]]), 0 <= i <= n, 0 < j <= vf, r[i] e in subarborele lui st[j]
int q = k - x - h[st[vf]];
for (int i = 1; i * i <= q; i++)
if (q % i == 0 && (solve(i) || solve(q / i)))
return 1;
return 0;
}
void dfs1(int x) {
G[x] = ++cnt;
for (auto &y : g[x]) {
h[y] += h[x];
dfs1(y);
}
D[x] = cnt;
}
void dfs2(int x) {
st[++vf] = x;
for (auto &y : g[x])
dfs2(y);
for (auto &y : e[x])
ans[y] = (check0(v[y]) || check1(v[y]) || check2(v[y]));
vf--;
}
int main() {
int m;
fscanf(fin, "%d%d%d%d", &n, &m, &k, &l);
l++;
for (int i = 1; i <= n; i++) {
int x;
fscanf(fin, "%d%d", &x, &h[i]);
h[i]++;
g[x].push_back(i);
}
for (int i = 0; i < m; i++) {
int x;
fscanf(fin, "%d%d", &x, &v[i]);
v[i]++;
e[x].push_back(i);
}
dfs1(0);
for (int i = 0; i <= n; i++)
r[i] = i;
std::sort(r, r + n + 1, cmp);
dfs2(0);
for (int i = 0; i < m; i++)
fputs(sir[ans[i]], fout);
fclose(fin);
fclose(fout);
return 0;
}
