#include<bits/stdc++.h>
using namespace std;
#define FO(x) {freopen(#x".in","r",stdin);freopen(#x".out","w",stdout);}
#define pa pair<int,int>
#define mod 1000000007
#define ll long long
#define mk make_pair
#define pb push_back
#define fi first
#define se second
#define lb double
#define cl(x) memset(x,0,sizeof x)
#ifdef Devil_Gary
#define bug(x) cout<<(#x)<<" "<<(x)<<endl
#define debug(...) fprintf(stderr, __VA_ARGS__)
#else
#define bug(x)
#define debug(...)
#endif
const int INF = 0x7fffffff;
const int N=1e6+5;
const lb alpha=0.85;
/*
char *TT,*mo,but[(1<<15)+2];
#define getchar() ((TT==mo&&(mo=(TT=but)+fread(but,1,1<<15,stdin),TT==mo))?-1:*TT++)//*/
inline int read(){
    int x=0,rev=0,ch=getchar();
    while(ch<'0'||ch>'9'){if(ch=='-')rev=1;ch=getchar();}
    while(ch>='0'&&ch<='9'){x=(x<<1)+(x<<3)+ch-'0';ch=getchar();}
    return rev?-x:x;
}
char s[N],ss[5];
int n,m,len,typ,lstans,sit[N],at[N];
lb v[N];
struct SuffixBT{
    int ls[N],rs[N],sz[N],sf[N],rt,cnt;
    int tmp[N],cc;
    int fail,fafail;
    lb fl,fr;
    bool cmp(int x,int y){
        if(!x||!y) return !x;
        if(s[x]!=s[y]) return s[x]<s[y];
        return v[at[x-1]]<v[at[y-1]];
    }
    void update(int pos,lb l,lb r){
        sz[pos]=sz[ls[pos]]+sz[rs[pos]]+1;
        if(max(sz[ls[pos]],sz[rs[pos]])>sz[pos]*alpha) fail=pos,fafail=-1,fl=l,fr=r;
        else if(fail==ls[pos]||fail==rs[pos]) fafail=pos;
    }
    void insert(int&pos,lb l,lb r,int&id){
        if(!pos){
            v[at[id]=pos=++cnt]=(l+r)/2.0,sz[pos]=1,sf[pos]=id;
            return;
        }
        lb vmid=(l+r)/2.0;
        cmp(sf[pos],id)?insert(rs[pos],vmid,r,id):insert(ls[pos],l,vmid,id);
        update(pos,l,r);;
    }
    int rebuild(int nl,int nr,lb l,lb r){
        int mid=nl+nr>>1,pos=tmp[mid];
        lb vmid=(l+r)/2.0;
        v[pos]=vmid,sz[pos]=nr-nl+1;
        if(nl<mid) ls[pos]=rebuild(nl,mid-1,l,vmid);
        if(nr>mid) rs[pos]=rebuild(mid+1,nr,vmid,r);
        return pos;
    }
    void dfs(int pos){
        if(ls[pos]) dfs(ls[pos]);
        tmp[++cc]=pos;
        if(rs[pos]) dfs(rs[pos]);
        ls[pos]=rs[pos]=sz[pos]=0;
    }
    void insert(int &id){
        fail=0,fafail=-1,insert(rt,0,1,id);
        if(fail){
            cc=0,dfs(fail);
            if(fafail!=-1) (fail==ls[fafail])? ls[fafail]=rebuild(1,cc,fl,fr):rs[fafail]=rebuild(1,cc,fl,fr);
            else rt=rebuild(1,cc,0,1);
        }
    }
}sbt;
struct SGT{
    int t[N<<2];
    bool cmp(int a,int b){
        if(sit[a]==sit[b]) return a<b;
        return v[at[sit[a]]]<v[at[sit[b]]];
    }
    void update(int pos){
        t[pos]=cmp(t[pos<<1],t[pos<<1|1])?t[pos<<1]:t[pos<<1|1];
    }
    void build(int pos,int l,int r){
        if(l==r){
            t[pos]=l;
            return;
        }
        int mid=l+r>>1;
        build(pos<<1,l,mid),build(pos<<1|1,mid+1,r),update(pos);
    }
    void modify(int pos,int l,int r,int x){
        if(l==r) return;
        int mid=l+r>>1;
        if(x<=mid) modify(pos<<1,l,mid,x);
        else modify(pos<<1|1,mid+1,r,x);
        update(pos);
    }
    int Query(int pos,int l,int r,int nl,int nr){
        if(nl<=l&&r<=nr) return t[pos];
        int mid=l+r>>1;
        if(nr<=mid) return Query(pos<<1,l,mid,nl,nr);
        else if(nl>mid) return Query(pos<<1|1,mid+1,r,nl,nr);
        int ql=Query(pos<<1,l,mid,nl,nr),qr=Query(pos<<1|1,mid+1,r,nl,nr);
        return cmp(ql,qr)?ql:qr;
    }
}sgt;
int main(){
#ifdef Devil_Gary
    freopen("in.txt","r",stdin);
#endif
    n=read(),m=read(),len=read(),typ=read(),scanf("%s",s+1),reverse(s+1,s+len+1);
    for(int i=0;i<=len;i++) s[i]-='a',sbt.insert(i);
    for(int i=1;i<=n;i++) sit[i]=read();
    sgt.build(1,1,n);
    for(int i=1,c,x,l,r;i<=m;i++){
        scanf("%s",ss);
        if(ss[0]=='I'){
            c=read();
            if(typ) c^=lstans;
            s[++len]=c,sbt.insert(len);
        }
        else if(ss[0]=='C') x=read(),sit[x]=read(),sgt.modify(1,1,n,x);
        else if(ss[0]=='Q') l=read(),r=read(),printf("%d\n",lstans=sgt.Query(1,1,n,l,r));
    }
    return 0;
}