#include <bits/stdc++.h>
#define startt ios_base::sync_with_stdio(false);cin.tie(0);
typedef long long ll;
using namespace std;
#define vint vector<int>
#define all(v) v.begin(), v.end()
#define MOD 1000000007
#define MOD2 998244353
#define MX 1000000000
#define MXL 1000000000000000000
#define PI (ld)2*acos(0.0)
#define pb push_back
#define sc second
#define fr first
#define int long long
#define endl '\n'
#define ld long double
#define NO cout << "NO" << endl
#define YES cout << "YES" << endl
int ceildiv(int one, int two) {if (one % two == 0) {return one / two;}else {return one / two + 1;}} int power(int n, int pow, int m) {if (pow == 0) return 1;if (pow % 2 == 0) {ll x = power(n, pow / 2, m);return (x * x) % m;}else return (power(n, pow - 1, m) * n) % m;} int gcd(int a, int b) { if (!b)return a; return gcd(b, a % b);} int factorial(int n, int mod) {if (n > 1)return (n * factorial(n - 1, mod)) % mod; else return 1;} int lcm(int a, int b) {return (a * b) / gcd(a, b);} vector<int> read(int n) {vector<int> a; for (int i = 0; i < n; i++) { int x; cin >> x; a.pb(x);} return a;}struct prefix_sum{vint pref;void build(vint a){pref.pb(0);for(int i = 0; i < a.size(); i++){pref.pb(pref.back()+a[i]);}}int get(int l, int r){return pref[r]-pref[l-1];}};//mesanu
struct node
{
int sum, pref, suff, ans;
node(int ans_, int sum_, int pref_, int suff_) : ans(ans_), sum(sum_), pref(pref_), suff(suff_) {}
};
struct segtree
{
int n;
vector<node> tree;
segtree(string s)
{
n = s.size();
n = 1<<(32-__builtin_clz(n));
tree.assign(2*n, node(0, 0, 0, 0));
for(int i = 0; i < s.size(); i++)
{
if(s[i] == 'T')
{
tree[i+n] = node(1, 1, 1, 1);
}
else
{
tree[i+n] = node(0, -1, 0, 0);
}
}
for(int i = n-1; i >= 1; i--)
{
tree[i] = combine(tree[2*i], tree[2*i+1]);
}
}
node combine(node a, node b)
{
node now = node(0, 0, 0, 0);
now.sum = a.sum+b.sum;
now.pref = max(a.pref, a.sum+b.pref);
now.suff = max(b.suff, a.suff+b.sum);
now.ans = max({a.pref+b.suff, a.sum+b.ans, a.ans+b.sum});
return now;
}
node get(int i, int l, int r, int tl, int tr)
{
if(tr < l)
{
return node(0, 0, 0, 0);
}
if(tl > r)
{
return node(0, 0, 0, 0);
}
if(tl <= l && tr >= r)
{
return tree[i];
}
int mid = l+r>>1;
return combine(get(2*i, l, mid, tl, tr), get(2*i+1, mid+1, r, tl, tr));
}
node query(int l, int r)
{
return get(1, 0, n-1, l, r);
}
};
void solve()
{
int n;
cin >> n;
string s;
cin >> s;
segtree bruh(s);
int q;
cin >> q;
while(q--)
{
int l, r;
cin >> l >> r;
l--;
r--;
cout << bruh.query(l, r).ans << endl;
}
}
int32_t main(){
startt
int t = 1;
//cin >> t;
while (t--) {
solve();
}
}
/*
11
CCCTTTTTTCC
3
1 11
4 9
1 6
*/
