#include<cstdio>

 #include<algorithm>

 #include<cstring>

 #include<cmath>

 #include<iostream>

 #include<cctype>

 #include<set>

 #include<vector>

 #include<queue>

 #include<map>

 #define pa pair<int,int>

 #define mp(a,b) make_pair(a,b)

 using namespace std;

 typedef long long LL;

 inline int read() {

     int x=,f=;char ch=getchar();for(;!isdigit(ch);ch=getchar())if(ch=='-')f=-;

     for(;isdigit(ch);ch=getchar())x=x*+ch-'';return x*f;

 }

 const int N = ;

 int head[N], nxt[N], to[N], En;

 int fa[N], siz[N], son[N], deth[N], ans[N], cnt[N][], ch[N];

 char s[N];

 vector< pa > q[N];

 void add_edge(int u,int v) {

     ++En; to[En] = v; nxt[En] = head[u]; head[u] = En;

 }

 void dfs(int u,int fa) {

     siz[u] = ;

     deth[u] = deth[fa] + ;

     for (int i=head[u]; i; i=nxt[i]) {

         int v = to[i];

         dfs(v, u);

         siz[u] += siz[v];

         if (!son[u] || siz[son[u]] < siz[v]) son[u] = v;

     }

 }

 void add(int u) {

     cnt[deth[u]][ch[u]] ++;

 }

 void Calc(int u) {

     add(u);

     for (int i=head[u]; i; i=nxt[i]) Calc(to[i]);

 }

 void Clear(int u) {

     cnt[deth[u]][ch[u]] --;

     for (int i=head[u]; i; i=nxt[i]) Clear(to[i]);

 }

 void solve(int u,bool c) {

     for (int i=head[u]; i; i=nxt[i])

         if (to[i] != son[u]) solve(to[i], );

     if (son[u]) solve(son[u], );

     for (int i=head[u]; i; i=nxt[i])

         if (to[i] != son[u]) Calc(to[i]);

     add(u);

     for (int i=,sz=q[u].size(); i<sz; ++i) {

         int flag = , id = q[u][i].second, h = q[u][i].first;

         for (int j=; j<; ++j) if (cnt[h][j] & ) flag ++;

         ans[id] = (flag <= );

     }

     if (!c) Clear(u);

 }

 int main() {

     int n = read(), Q = read();

     for (int i=; i<=n; ++i) {

         int u = read();

         add_edge(u, i);

     }

     scanf("%s",s + );

     for (int i=; i<=n; ++i) ch[i] = s[i] - 'a';

     for (int i=; i<=Q; ++i) {

         int v = read(), h = read();

         q[v].push_back(mp(h, i));

     }

     dfs(, );

     solve(, );

     for (int i=; i<=Q; ++i) puts(ans[i] ? "Yes" : "No");

     return ;

 }