int main() {
int n, m, l, r;
set<pair<int, int> > st;
scanf("%d%d", &n, &m);
scanf("%s", buf);
sa.init(n, buf);
rmq.init(n, sa.height);
l = 0;
r = 1;
for (int i = 0; i < m; ++i) {
scanf("%s", op);
int& t = op[0] == 'L' ? l : r;
t += op[1] == '+' ? 1 : -1;
int k = sa.rank[l];
int lo = 0, hi = k;
while (lo < hi) {
int mi = (lo + hi) / 2;
if (rmq.value(mi + 1, k + 1) >= r - l) {
hi = mi;
} else {
lo = mi + 1;
}
}
st.insert(make_pair(hi, r - l));
}
printf("%d\n", (int)st.size());
return 0;
}
int lca(int i, int j) {
i = u[i];
j = u[j];
if (i > j) {
swap(i, j);
}
return j2i[rmq.value(i, j + 1)];
}
