#include <bits/stdc++.h>
using namespace std;
vector<pair<int, int> > q[500005];
int n, m, tot, nms, ans[500005], dep[500005], ms[500005], sz[500005],
    t[500005][30], a[500005], hd[500005], to[500005], nxt[500005];
char ch[500005];
int read() {
  int x = 0, fl = 1;
  char ch = getchar();
  while (ch < '0' || ch > '9') {
    if (ch == '-') fl = -1;
    ch = getchar();
  }
  while (ch >= '0' && ch <= '9') {
    x = (x << 1) + (x << 3) + ch - '0';
    ch = getchar();
  }
  return x * fl;
}
void add(int x, int y) {
  tot++;
  to[tot] = y;
  nxt[tot] = hd[x];
  hd[x] = tot;
  return;
}
void dfs(int x, int f) {
  sz[x] = 1;
  int mx = 0;
  for (int i = hd[x]; i; i = nxt[i]) {
    int y = to[i];
    if (y == f) continue;
    dep[y] = dep[x] + 1, dfs(y, x);
    sz[x] += sz[y];
    if (sz[y] > mx) mx = sz[y], ms[x] = y;
  }
  return;
}
void calc(int x, int f, int o) {
  t[dep[x]][a[x]] += o;
  for (int i = hd[x]; i; i = nxt[i]) {
    int y = to[i];
    if (y == f || y == nms) continue;
    calc(y, x, o);
  }
  return;
}
void dsu(int x, int f, int o) {
  for (int i = hd[x]; i; i = nxt[i]) {
    int y = to[i];
    if (y == f || y == ms[x]) continue;
    dsu(y, x, -1);
  }
  if (ms[x]) dsu(ms[x], x, 1), nms = ms[x];
  calc(x, f, 1), nms = 0;
  for (int p = 0; p < (int)q[x].size(); p++) {
    int d = q[x][p].first, id = q[x][p].second, cnt = 0;
    for (int i = 1; i <= 26; i++) cnt += (t[d][i] & 1);
    ans[id] = (cnt <= 1);
  }
  if (o == -1) calc(x, f, -1);
  return;
}
int main() {
  n = read(), m = read();
  for (int i = 2; i <= n; i++) {
    int x = read();
    add(x, i);
  }
  scanf("%s", ch + 1);
  for (int i = 1; i <= n; i++) a[i] = ch[i] - 'a' + 1;
  for (int i = 1; i <= m; i++) {
    int x = read(), y = read();
    q[x].push_back(make_pair(y, i));
  }
  dep[1] = 1, dfs(1, 0), dsu(1, 0, -1);
  for (int i = 1; i <= m; i++) printf("%s\n", ans[i] ? "Yes" : "No");
  return 0;
}
