#include <bits/stdc++.h>
using namespace std;
#define f first
#define s second
#define pb push_back
#define ar array
#define all(x) x.begin(), x.end()
#define siz(x) (int)x.size()
#define FOR(x, y, z) for(int x = (y); x < (z); x++)
#define ROF(x, z, y) for(int x = (y-1); x >= (z); x--)
#define F0R(x, z) FOR(x, 0, z)
#define R0F(x, z) ROF(x, 0, z)
#define trav(x, y) for(auto&x:y)
using ll = long long;
using vi = vector<int>;
using vl = vector<long long>;
using pii = pair<int, int>;
using vpii = vector<pair<int, int>>;
template<class T> inline bool ckmin(T&a, T b) {return b < a ? a = b, 1 : 0;}
template<class T> inline bool ckmax(T&a, T b) {return b > a ? a = b, 1 : 0;}
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
const char nl = '\n';
const int mxN = 2e5 + 10;
const int MOD = 1e9 + 7;
const long long infLL = 1e18;
struct Tree {
typedef pii T;
T Unit = {0, 0};
T f(T a, T b) { return {a.f+b.f, max(a.s, a.f+b.s)}; } // (any associative fn)
vector<T> s; int n;
Tree(int n = 0) : s(2*n, Unit), n(n) {}
void update(int pos, T val) {
for (s[pos += n] = val; pos /= 2;)
s[pos] = f(s[pos * 2], s[pos * 2 + 1]);
}
T query(int b, int e) { // query [b, e)
T ra = Unit, rb = Unit;
for (b += n, e += n; b < e; b /= 2, e /= 2) {
if (b % 2) ra = f(ra, s[b++]);
if (e % 2) rb = f(s[--e], rb);
}
return f(ra, rb);
}
};
typedef int node;
struct BIT{
//ask for queries 0 idxed or remove ++idx/++r
vector<node> bit;
int n;
void init(int x){
n=x+1;
bit.assign(n + 1,0);
}
node sum(int r){
node ret = 0;
for(r++; r ; r -= r & -r){
ret += bit[r];
}
return ret;
}
node sum(int l, int r){
return sum(r) - sum(l-1);
}
void add(int idx, node delta){
for(idx++; idx < n; idx += idx & -idx){
bit[idx] += delta;
}
}
}bit;
int32_t main(){
ios_base::sync_with_stdio(0); cin.tie(0);
int n; string s;
cin >> n; cin >> s;
int q; cin >> q;
vector<vpii> qq(n);
F0R(i, q){
int l, r;
cin >> l >> r;
l--; r--;
qq[r].pb({l, i});
}
Tree seg(n);
bit.init(n);
stack<int> vals;
vi ans(q);
F0R(i, n){
if(s[i]=='C'){
seg.update(i, pii{-1, 0});
if(!vals.empty()){
int T = vals.top(); vals.pop();
seg.update(T, {1, 1});
bit.add(T, -1);
//cout << "WE GOT HERE" << endl;
}
}
else{
vals.push(i);
bit.add(i, 1);
}
trav(v, qq[i]){
int r = bit.sum(v.f, i);
//cout << bit.sum(i, v.f) << ' ' << seg.query(i, v.f+1).s << nl;
r += seg.query(v.f, i+1).s;
ans[v.s] = r;
}
}
trav(x, ans) cout << x << nl;
return 0;
}
