#include <bits/stdc++.h>
using namespace std;
#define for_(i, s, e) for (int i = s; i < (int) e; i++)
#define for__(i, s, e) for (ll i = s; i < e; i++)
typedef long long ll;
typedef vector<int> vi;
typedef array<int, 2> ii;
//#define endl '\n'
struct Node {
int pref = 0, sum = 0;
};
class SegmentTree {
public:
//private:
vector<Node> tree; int n;
Node bound = {0, 0};
static Node merge(Node a, Node b) {
Node ans;
ans.sum = a.sum + b.sum;
ans.pref = max(a.pref, a.sum + b.pref);
return ans;
}
void update(int i, int val, int l, int r, int p) {
if (l > i or r < i) return;
if (l == r) {
tree[p] = {val, val};
return;
}
int mid = (l + r) / 2;
int c1 = 2*p+1, c2 = 2*p+2;
update(i, val, l, mid, c1); update(i, val, mid+1, r, c2);
tree[p] = merge(tree[c1], tree[c2]);
}
Node mx(int i, int j, int l, int r, int p) {
if (l > j or r < i) return bound;
if (l >= i and r <= j) return tree[p];
int mid = (l + r) / 2;
int c1 = 2*p+1, c2 = 2*p+2;
return merge(mx(i, j, l, mid, c1), mx(i, j, mid+1, r, c2));
}
//public:
SegmentTree(int _n) {
n = _n;
tree.resize(4*n, bound);
}
Node mx(int i, int j) {
return mx(i, j, 0, n-1, 0);
}
void update(int i, int val) {
update(i, val, 0, n-1, 0);
}
};
int main() {
#ifdef mlocal
freopen("test.in", "r", stdin);
#endif
ios_base::sync_with_stdio(false);
cin.tie(0);
int n; cin >> n;
vi nums(n);
for_(i, 0, n) {
char c; cin >> c;
nums[i] = c == 'C' ? 1 : -1;
}
SegmentTree tree(n);
int q; cin >> q;
vector<vector<ii>> ends(n);
for_(i, 0, q) {
int l, r; cin >> l >> r;
ends[l-1].push_back({r-1, i});
}
vi out(q);
vi st;
for (int i = n-1; i >= 0; i--) {
if (nums[i] == -1) st.push_back(i);
else {
tree.update(i, 1);
if (st.size()) {
tree.update(st.back(), -1);
st.pop_back();
}
}
int ans = st.size();
for (auto &r: ends[i]) {
// cout << "updating " << r[1] << endl;
Node temp = tree.mx(i, r[0]);
out[r[1]] = temp.pref - temp.sum;
for (auto j: st) if (j <= r[0]) out[r[1]]++;
}
}
for (auto i: out) cout << i << endl;
cout << endl;
// cout << ans + tree.mx(0, n-1) - tree.tree[0].sum << endl;
}
