#include <bits/stdc++.h>
using namespace std;
const int maxn = 5e5 + 10;
int n;
string s;
bool visited[maxn];
int arr[maxn];
int solve(int S, int E){
int balance = 0;
int ret = 0;
memset(visited, false, sizeof visited);
for(int i = S; i <= E; i ++){
if(s[i] == 'C'){
balance ++;
arr[i] = 1;
}
else{
balance --;
arr[i] = -1;
}
if(balance < 0){
balance = 0;
visited[i] = true;
// arr[i] = 0;
ret ++;
}
}
int suff_sum = 0;
int mnn = (1 << 30);
for(int i = S; i <= S; i ++){
suff_sum += arr[i];
// mnn = min(mnn, min(0, -suff_sum));
}
balance = 0;
for(int i = E; i >= S; i --){
if(s[i] == 'C'){
balance ++;
}
else if(!visited[i] and s[i] == 'T'){
balance --;
}
// cout << balance << " " ;
mnn = min(mnn, min(0, -balance));
if(balance < 0){
balance = 0;
// ret ++;
}
}
return ret + abs(mnn);
}
struct elem{
int L, R, sum, min_suf;
elem(){
L = R = sum = min_suf = 0;
}
};
elem mymerge(elem A, elem B){
elem ret;
ret.R = max(A.R, B.R - A.min_suf);
ret.sum = max(B.sum, A.sum - B.min_suf);
ret.min_suf = A.min_suf + B.min_suf;
ret.L = max(max(A.L - B.min_suf, B.L - A.min_suf), A.R + B.sum);
return ret;
}
class node{
public:
elem val;
int lb, rb;
node *left, *right;
node(int levo, int desno){
lb = levo;
rb = desno;
if(levo == desno){
if(s[levo] == 'T'){
val.L = val.R = val.sum = 1;
val.min_suf = -1;
}
else{
val.L = val.R = val.sum = 0;
val.min_suf = 1;
}
}
else{
int mid = (levo + desno) >> 1;
left = new node(levo, mid);
right = new node(mid + 1, desno);
val = mymerge(left -> val, right -> val);
}
}
elem query(int i, int j){
if(i <= lb and rb <= j){
return val;
}
/// i j l r i j
if(j < lb or rb < i){
return elem();
}
return mymerge(left -> query(i, j), right -> query(i, j));
}
};
int main()
{
ios_base::sync_with_stdio(false);
//ifstream cin("in.txt.txt");
cin >> n >> s;
int q;
cin >> q;
node *root = new node(0, n - 1);
for(int i = 0; i < q; i ++){
int a, b;
cin >> a >> b;
a --;
b --;
cout << root -> query(a, b).L << endl;
}
return 0;
}
