#include <bits/stdc++.h>
using namespace std;
inline int Read() {
  int x(0), f(1);
  char c(getchar());
  while (c < '0' || '9' < c) {
    if (c == '-') {
      f = -1;
    }
    c = getchar();
  }
  while ('0' <= c && c <= '9') {
    x = (x << 1) + (x << 3) + c - '0';
    c = getchar();
  }
  return f * x;
}
void Write(int x) {
  if (x < 0) {
    printf("-");
    x = -x;
  }
  if (9 < x) {
    Write(x / 10);
  }
  putchar(x % 10 + '0');
}
inline void Writeln(int x) {
  Write(x);
  puts("");
}
const int MAXN = 5e5 + 5;
const int MAXM = MAXN << 1;
int n, m;
char val[MAXN];
int sum[MAXN];
struct Query {
  int deep, id;
  Query(int deep, int id) : deep(deep), id(id) {}
};
vector<Query> query[MAXN];
struct Edge {
  int to, next;
} edge[MAXM];
int edge_head[MAXN];
int edge_cnt = 0;
void AddEdge(int form, int to) {
  edge[++edge_cnt].to = to;
  edge[edge_cnt].next = edge_head[form];
  edge_head[form] = edge_cnt;
}
int son[MAXN];
int size[MAXN];
int deep[MAXN];
bool Check(int a) { return a == (a & -a); }
void DFS_1(int now = 1, int father = 0) {
  deep[now] = deep[father] + 1;
  size[now] = 1;
  for (int edge_i = edge_head[now]; edge_i; edge_i = edge[edge_i].next) {
    if (edge[edge_i].to ^ father) {
      DFS_1(edge[edge_i].to, now);
      size[now] += size[edge[edge_i].to];
      if (size[son[now]] < size[edge[edge_i].to]) {
        son[now] = edge[edge_i].to;
      }
    }
  }
}
int im_son;
int answer[MAXN];
void Add(int now, int father) {
  sum[deep[now]] ^= 2 << (val[now] - 'a');
  for (int edge_i = edge_head[now]; edge_i; edge_i = edge[edge_i].next) {
    if (edge[edge_i].to ^ father && edge[edge_i].to ^ im_son) {
      Add(edge[edge_i].to, now);
    }
  }
}
void Delete(int now, int father, bool flag = 1) {
  sum[deep[now]] ^= 2 << (val[now] - 'a');
  for (int edge_i = edge_head[now]; edge_i; edge_i = edge[edge_i].next) {
    if (edge[edge_i].to ^ father && edge[edge_i].to ^ im_son) {
      Delete(edge[edge_i].to, now, 0);
    }
  }
}
void DFS_2(int now = 1, int father = 0, int opt = 0) {
  for (int edge_i = edge_head[now]; edge_i; edge_i = edge[edge_i].next) {
    if (edge[edge_i].to ^ father && edge[edge_i].to ^ son[now]) {
      DFS_2(edge[edge_i].to, now, 1);
    }
  }
  if (son[now]) {
    DFS_2(son[now], now, 0);
  }
  im_son = son[now];
  Add(now, father);
  if (query[now].size()) {
    for (int i = 0; i <= query[now].size() - 1; ++i) {
      answer[query[now][i].id] = Check(sum[query[now][i].deep]);
    }
  }
  im_son = 0;
  if (opt) {
    Delete(now, father);
  }
}
int main() {
  scanf("%d%d", &n, &m);
  int father;
  for (int i = 2; i <= n; ++i) {
    scanf("%d", &father);
    AddEdge(father, i);
  }
  scanf("%s", val + 1);
  int u, deep;
  for (int i = 1; i <= m; ++i) {
    scanf("%d%d", &u, &deep);
    query[u].push_back(Query{deep, i});
  }
  DFS_1();
  DFS_2();
  for (int i = 1; i <= m; ++i) {
    if (answer[i]) {
      printf("Yes\n");
    } else {
      printf("No\n");
    }
  }
  return 0;
}
