#include<cstdio>
#include<algorithm>
#include<stack>
#include<vector>
using namespace std;
typedef long long ll;
const int N=300001,M=2000;
int n,m,fa[N],fa2[N],f[N],g[N],f1[N],f2[N],g1[N],g2[N],d1[N],d2[N],*p1[N],*p2[N];
ll v;
char b[N];
bool h[N],h2[N];
vector<int> a[N],a2[N];
stack<int> S;
struct
{
    int x,c;
}e[N];
bool dfs0(int x,int w)
{
    f[x]=0,g[x]=-w;
    if(b[x]!='C') ++w;
    int u=h[x];
    for(auto i:a[x])
    {
        u+=dfs0(i,w);
        f[x]+=f[i];
        if(b[i]!='A') ++f[x];
    }
    g[x]+=f[x];
    if(u>=2) h[x]=true;
    return u>0;
}
void add(int &f0,int &g0,int *p0,int x)
{
    if(b[x]=='A') ++f0;
    if(b[x]=='?')
    {
        if(g[x]>0) ++g0;
        if(abs(g[x])<=M) ++p0[g[x]];
    }
}
int dfs(int x)
{
    if(!h[x])
    {
        S.push(x);
        int u=0;
        for(auto i:a[x]) u+=dfs(i);
        return u;
    }
    S.push(x);
    p1[x]=(new int[M*2+10])+(M+5);
    for(int i=-M;i<=M;++i) p1[x][i]=0;
    p2[x]=(new int[M*2+10])+(M+5);
    for(int i=-M;i<=M;++i) p2[x][i]=0;
    if(x!=1)
    {
        int z=fa[x];
        while(!h[z])
        {
            add(f1[x],g1[x],p1[x],z);
            h2[z]=true;
            z=fa[z];
        }
    }
    for(auto i:a[x])
    {
        int z=dfs(i);
        if(z)
        {
            a2[x].push_back(z);
            fa2[z]=x;
        }
    }
    while(S.top()!=x)
    {
        if(h2[S.top()]==false) add(f2[x],g2[x],p2[x],S.top());
        S.pop();
    }
    S.pop();
    return x;
}
void add1(int &g,int &d,int *p,int k)
{
    if(k==1)
    {
        g+=p[-d];
        ++d;
        v+=g;
    }
    else if(k==-1)
    {
        v-=g;
        --d;
        g-=p[-d];
    }
}
void solve1(int x,int k)
{
    while(x!=1)
    {
        v+=(ll)f1[x]*k;
        add1(g1[x],d1[x],p1[x],k);
        x=fa2[x];
        f[x]+=k,g[x]+=k;
    }
}
void solve2(int x,int k)
{
    add1(g2[x],d2[x],p2[x],k);
    for(auto i:a2[x])
    {
        add1(g1[i],d1[i],p1[i],k);
        g[i]+=k;
        solve2(i,k);
    }
}
void solve(int l,int r)
{
    for(int i=1;i<=n;++i)
    {
        f1[i]=f2[i]=g1[i]=g2[i]=d1[i]=d2[i]=0;
        if(p1[i]!=NULL) delete[] p1[i],p1[i]=NULL;
        if(p2[i]!=NULL) delete[] p2[i],p2[i]=NULL;
        h[i]=h2[i]=false;
        a2[i].clear();
    }
    while(!S.empty()) S.pop();
    v=0;
    for(int i=l;i<=r;++i) h[e[i].x]=true;
    h[1]=true;
    dfs0(1,0);
    dfs(1);
    vector<int> p;
    for(int i=1;i<=n;++i)
    {
        if(h[i]) p.push_back(i);
        else if(b[i]=='A') v+=f[i];
        else if(b[i]=='?') v+=max(g[i],0);
    }
    for(int i=l;i<=r;++i)
    {
        int x=e[i].x,c=e[i].c;
        if((b[x]!='A')^(c!='A'))
        {
            solve1(x,b[x]!='A'?-1:1);
        }
        if((b[x]!='C')^(c!='C'))
        {
            solve2(x,b[x]!='C'?1:-1);
        }
        b[x]=c;
        ll w=v;
        for(auto j:p)
        {
            if(b[j]=='A') w+=f[j];
            else if(b[j]=='?') w+=max(g[j],0);
        }
        printf("%lld\n",w);
    }
}
int main()
{
    scanf("%d%d%s",&n,&m,b+1);
    for(int i=2;i<=n;++i)
    {
        int x;
        scanf("%d",&x);
        a[x].push_back(i);
        fa[i]=x;
    }
    for(int i=1;i<=m;++i)
    {
        scanf("%d%s",&e[i].x,&e[i].c);
    }
    for(int i=1;i<=m;++i)
    {
        int j=min(i+M-1,m);
        solve(i,j);
        i=j;
    }
    return 0;
}