#include<bits/stdc++.h>
#define Gc() getchar() 
#define Me(x,y) memset(x,y,sizeof(x))
#define Mc(x,y) memcpy(x,y,sizeof(x))
#define d(x,y) ((m)*(x-1)+(y))
#define R(n) (rnd()%(n)+1)
#define Pc(x) putchar(x)
#define LB lower_bound
#define UB upper_bound
#define fi first
#define se second
using namespace std;using ll=long long;using db=double;using lb=long db;using ui=unsigned;using ull=unsigned long long;using pii=pair<int,int>;using LL=__int128;
const int N=3e5+5,M=3e5+5,K=(1<<15)+5,mod=1e9+7,Mod=mod-1;const db eps=1e-9;const int INF=1e9+7;mt19937 rnd(time(0));
int n,m,fa[N];char s[N];vector<int> S[N];
ll ans,tot;
void Make(int x,int w){
	if(s[x]=='A') w++;
	if(s[x]=='C'||s[x]=='?') ans+=w;
	for(int i:S[x]) Make(i,w);
}
int Si[N];
void dfs(int x,int w){
	Si[x]=0;
	for(int i:S[x]) dfs(i,w+(s[x]=='A'||s[x]=='?')),Si[x]+=Si[i];
	if(s[x]=='?') ans+=max(Si[x]-w,0);
	Si[x]+=(s[x]=='C'||s[x]=='?');
}
void Solve(){
	int i,j;scanf("%d%d",&n,&m);
	scanf("%s",s+1);
	for(i=2;i<=n;i++) scanf("%d",&fa[i]),S[fa[i]].emplace_back(i);
	for(i=1;i<=m;i++){
		int x;char c;scanf("%d",&x);Gc();s[x]=Gc();
		ans=tot=0;Make(1,0);dfs(1,0);
		printf("%lld\n",ans);
	}
}
int main(){
	int t;
	// scanf("%d",&t);
	t=1;
	while(t--) Solve();
	cerr<<clock()*1.0/CLOCKS_PER_SEC<<'\n';
}