/*
PROG: source
LANG: C++11
_____
.' '.
/ 0 0 \
| ^ |
| \ / |
\ '---' /
'._____.'
*/
#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
using namespace std;
using namespace __gnu_pbds;
struct chash
{
int operator()(int x) const
{
x ^= (x >> 20) ^ (x >> 12);
return x ^ (x >> 7) ^ (x >> 4);
}
int operator()(long long x) const
{
return x ^ (x >> 32);
}
};
template<typename T> using orderedset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template<typename T> using hashtable = gp_hash_table<T, T, chash>;
template<class T>
void readi(T &x)
{
T input = 0;
bool negative = false;
char c = ' ';
while (c < '-')
{
c = getchar();
}
if (c == '-')
{
negative = true;
c = getchar();
}
while (c >= '0')
{
input = input * 10 + (c - '0');
c = getchar();
}
if (negative)
{
input = -input;
}
x = input;
}
template<class T>
void printi(T output)
{
if (output == 0)
{
putchar('0');
return;
}
if (output < 0)
{
putchar('-');
output = -output;
}
int aout[20];
int ilen = 0;
while(output)
{
aout[ilen] = ((output % 10));
output /= 10;
ilen++;
}
for (int i = ilen - 1; i >= 0; i--)
{
putchar(aout[i] + '0');
}
return;
}
template<class T>
void ckmin(T &a, T b)
{
a = min(a, b);
}
template<class T>
void ckmax(T &a, T b)
{
a = max(a, b);
}
template<class T>
T normalize(T x, T mod = 1000000007)
{
return (((x % mod) + mod) % mod);
}
long long randomizell(long long mod)
{
return ((1ll << 45) * rand() + (1ll << 30) * rand() + (1ll << 15) * rand() + rand()) % mod;
}
int randomize(int mod)
{
return ((1ll << 15) * rand() + rand()) % mod;
}
#define y0 ___y0
#define y1 ___y1
#define MP make_pair
#define MT make_tuple
#define PB push_back
#define PF push_front
#define LB lower_bound
#define UB upper_bound
#define fi first
#define se second
#define debug(x) cerr << #x << " = " << x << endl;
const long double PI = 4.0 * atan(1.0);
const long double EPS = 1e-10;
#define MAGIC 347
#define SINF 10007
#define CO 1000007
#define INF 1000000007
#define BIG 1000000931
#define LARGE 1696969696967ll
#define GIANT 2564008813937411ll
#define LLINF 2696969696969696969ll
#define MAXN 500013
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef pair<ld, ld> pdd;
int N, Q;
int arr[MAXN];
vector<pii> quer[MAXN];
bool bad[MAXN];
vector<int> pos;
int ans[MAXN];
int inc;
int seg[4 * MAXN], lazy[4 * MAXN];
void push(int w, int L, int R)
{
seg[w] += lazy[w];
if (L != R)
{
lazy[2 * w] += lazy[w];
lazy[2 * w + 1] += lazy[w];
}
lazy[w] = 0;
return;
}
void update(int w, int L, int R, int a, int b, int v)
{
push(w, L, R);
if (b < L || R < a)
{
return;
}
if (a <= L && R <= b)
{
lazy[w] += v;
push(w, L, R);
return;
}
int mid = (L + R) / 2;
update(2 * w, L, mid, a, b, v);
update(2 * w + 1, mid + 1, R, a, b, v);
seg[w] = min(seg[2 * w], seg[2 * w + 1]);
}
int query(int w, int L, int R, int a, int b)
{
push(w, L, R);
if (b < L || R < a)
{
return INF;
}
if (a <= L && R <= b)
{
return seg[w];
}
int mid = (L + R) / 2;
return min(query(2 * w, L, mid, a, b), query(2 * w + 1, mid + 1, R, a, b));
}
int32_t main()
{
ios_base::sync_with_stdio(0);
srand(time(0));
// cout << fixed << setprecision(10);
// cerr << fixed << setprecision(10);
if (fopen("input.in", "r"))
{
freopen ("input.in", "r", stdin);
freopen ("output.out", "w", stdout);
}
cin >> N;
string temps;
cin >> temps;
for (int i = 0; i < N; i++)
{
if (temps[i] == 'C')
{
arr[i] = 1;
}
else
{
arr[i] = -1;
}
}
for (int i = 0; i < N; i++)
{
update(1, 0, N, 0, i, arr[i]);
}
cin >> Q;
for (int i = 0; i < Q; i++)
{
int l, r;
cin >> l >> r;
l--; r--;
quer[l].PB(MP(r, i));
}
pos.PB(N);
for (int i = N - 1; i >= 0; i--)
{
if (arr[i] == 1)
{
if (!pos.empty())
{
int idx = pos.back();
pos.pop_back();
update(1, 0, N, 0, idx, -1);
}
}
else
{
pos.PB(i);
update(1, 0, N, 0, i, 1);
}
//now answer all queries
for (pii p : quer[i])
{
// cerr << "qid " << p.se << endl;
// for (int x : pos)
// {
// cerr << x << ' ';
// }
// cerr << endl;
int qid = p.se, r = p.fi;
ans[qid] += pos.size();
// debug(r);
int lo = 0, hi = pos.size();
while(hi > lo)
{
// cerr << lo << ' ' << hi << endl;
int mid = (hi + lo + 1) / 2;
if (pos[mid - 1] <= r)
{
hi = mid - 1;
}
else
{
lo = mid;
}
}
// cerr << "lo = " << lo << endl;
ans[qid] -= lo;
ans[qid] -= (query(1, 0, N, i, r + 1) - query(1, 0, N, r + 1, r + 1));
}
}
for (int i = 0; i < Q; i++)
{
cout << ans[i] << '\n';
}
// cerr << "time elapsed = " << (clock() / (CLOCKS_PER_SEC / 1000)) << " ms" << endl;
return 0;
}
