#include <bits/stdc++.h>
using namespace std;
const int MAXN = 2e6;
struct Noeud
{
int iDeb, iFin;
int maxPref, maxSuff, totDelta, sol;
};
Noeud fusion(Noeud lhs, Noeud rhs)
{
Noeud ret;
ret.iDeb = lhs.iDeb;
ret.iFin = rhs.iFin;
ret.maxPref = max(lhs.maxPref, lhs.totDelta + rhs.maxPref);
ret.maxSuff = max(rhs.maxSuff, rhs.totDelta + lhs.maxSuff);
ret.sol = max({lhs.totDelta + rhs.sol, lhs.sol + rhs.totDelta, lhs.maxPref + rhs.maxSuff});
ret.totDelta = lhs.totDelta + rhs.totDelta;
return ret;
}
Noeud seg[MAXN];
string votes;
void construitArbre(int iNoeud, int iDeb, int iFin)
{
if (iDeb == iFin)
{
seg[iNoeud].iDeb = iDeb;
seg[iNoeud].iFin = iFin;
int val = votes[iDeb] == 'T' ? 1 : 0;
seg[iNoeud].maxPref = seg[iNoeud].maxSuff = seg[iNoeud].sol = seg[iNoeud].totDelta = val;
if (votes[iDeb] == 'C')
seg[iNoeud].totDelta = -1;
return;
}
construitArbre(2*iNoeud, iDeb, (iDeb+iFin)/2);
construitArbre(2*iNoeud+1, (iDeb+iFin)/2+1, iFin);
seg[iNoeud] = fusion(seg[2*iNoeud], seg[2*iNoeud+1]);
}
Noeud requete(int iNoeud, int iDeb, int iFin)
{
if (iDeb <= seg[iNoeud].iDeb and seg[iNoeud].iFin <= iFin)
return seg[iNoeud];
if (iDeb > seg[iNoeud].iFin or iFin < seg[iNoeud].iDeb)
return {0, 0, 0, 0, 0, 0};
return fusion(requete(2*iNoeud, iDeb, iFin), requete(2*iNoeud+1, iDeb, iFin));
}
signed main(void)
{
ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
int nbFans;
cin >> nbFans >> votes;
construitArbre(1, 0, nbFans-1);
int nbRequetes;
cin >> nbRequetes;
for (int iRequete = 0; iRequete < nbRequetes; ++iRequete)
{
int L, R;
cin >> L >> R;
cout << requete(1, L-1, R-1).sol << '\n';
}
}
