#include <iostream>
#include <vector>
using namespace std;
using vi = vector<int>;
const int inf = 1'000'000'000;
vi p, s;
struct sdata
{
int pmx = -inf;
int smx = -inf;
int ans = -inf;
};
sdata combine(sdata a, sdata b)
{
return {max(a.pmx, b.pmx), max(a.smx, b.smx), max(max(a.ans, b.ans), a.pmx + b.smx)};
}
struct segtree
{
int l;
int r;
sdata v;
segtree* left = NULL;
segtree* right = NULL;
segtree()
{
;
}
segtree(int L, int R)
{
l = L;
r = R;
if(l == r)
v = sdata{p[l], s[l], p[l]+s[l]};
else
{
int m = (l+r)/2;
left = new segtree(l, m);
right = new segtree(m+1, r);
v = combine(left->v, right->v);
}
}
sdata getrange(int L, int R)
{
if(L <= l && r <= R)
return v;
else if(R <= (l+r)/2)
return left->getrange(L, R);
else if(L >= (l+r)/2+1)
return right->getrange(L, R);
else
return combine(left->getrange(L, R), right->getrange(L, R));
}
};
int main()
{
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int N;
cin >> N;
vi A(1+N);
for(int i = 1; i <= N; i++)
{
char c;
cin >> c;
if(c == 'T')
A[i] = +1;
else
A[i] = -1;
}
p = vi(1+N);
p[0] = 0;
for(int i = 1; i <= N; i++)
p[i] = p[i-1] + A[i];
s = vi(1+N);
s[N] = 0;
for(int i = N-1; i >= 0; i--)
s[i] = s[i+1] + A[i+1];
segtree ST(0, N);
int Q;
cin >> Q;
for(int q = 1; q <= Q; q++)
{
int l, r;
cin >> l >> r;
sdata d = ST.getrange(l-1, r);
int pmx = d.pmx;
int c1 = pmx - p[l-1];
// cerr << "c1 = " << c1 << '\n';
// cerr << "pmx = " << pmx << '\n';
// int c2 = 0;
int res = +s[r] + p[l-1];
res = max(res, d.ans);
res -= s[r] + p[l-1];
res = max(res, c1);
cout << res << '\n';
}
}
