#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#define F first
#define S second
#define pb push_back
#define ppb pop_back
#define ep insert
#define endl '\n'
#define elif else if
#define pow pwr
#define sqrt sqrtt
#define int long long
#define ll long long
typedef unsigned long long ull;
using namespace std;
const int N=7005;
int n,m,q,a[N],p[N];
bool b[N];
int32_t main(){
ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
cin>>n>>m;
for (int i=1;i<=n;i++){
char c;cin>>c;
if (c=='R') b[i]=1;
}
for (int i=1;i<=m;i++) cin>>a[i];
cin>>q;
int s,e;
cin>>s>>e;
for (int i=s;i<=e;i++){
b[a[i]]=1;
int L=a[i],R=a[i];
bool h=1;
while (L && R<=n){
if (h){
while (b[R+1]==1) R++;
//cout<<L<<' '<<R<<endl;
p[L]++;
p[R+1]--;
R++;
h=!h;
}
else{
while (b[L-1]==0 && L>1) L--;
//cout<<L<<' '<<R<<endl;
p[L]++;
p[R+1]--;
L--;
h=!h;
}
}
for (int j=1;j<=n;j++){
p[j]+=p[j-1];
if (p[j]%2) b[j]^=1;
}
for (int j=1;j<=n;j++) p[j]=0;
}
int ans=0;
for (int i=1;i<=n;i++) ans+=b[i];
cout<<ans<<endl;
return 0;
}
