#include <bits/stdc++.h>
using namespace std;
const int MOD = 1e9 + 7;
//ubit cu se
void solve() {
int n;
cin>>n;
string s;
cin>>s;
vector<int> pre(n + 1), suf(n + 2), cSum(n + 1), tSum(n + 1);
for(int i = 0; i < n; i++){
cSum[i + 1] = cSum[i] + (s[i] == 'C');
tSum[i + 1] = tSum[i] + (s[i] == 'T');
pre[i + 1] = cSum[i + 1] - tSum[i + 1];
}
for(int i = n - 1; i >= 0; i--){
suf[i + 1] = suf[i + 2] + (s[i] == 'C') - (s[i] == 'T');
}
vector<int> bad_pre(n + 1, 0), bad_suf(n + 2, 0);
for(int i = 1; i <= n; i++) bad_pre[i] = min(bad_pre[i - 1], pre[i]);
for(int i = n; i >= 1; i--) bad_suf[i] = min(bad_suf[i + 1], suf[i]);
int q;
cin>>q;
while (q--) {
int l, r;
cin>>l>>r;
int totalC = cSum[r] - cSum[l - 1];
int totalT = tSum[r] - tSum[l - 1];
int low = 0, high = totalT, ans = totalT;
while(low <= high){
int mid = (low + high) / 2;
int c = 0, t = 0;
vector<int> del;
for(int i = l - 1; i < r && t < mid; i++){
if(s[i] == 'T'){
del.push_back(i);
t++;
}
}
vector<bool> skip(n, false);
for (int x : del) skip[x] = true;
bool valid = true;
c = 0, t = 0;
for(int i = l - 1; i < r; i++){
if(skip[i]) continue;
if(s[i] == 'C') c++;
else t++;
if(c < t){
valid = false;
break;
}
}
c = 0, t = 0;
for(int i = r - 1; i >= l - 1 && valid; i--){
if(skip[i]) continue;
if(s[i] == 'C') c++;
else t++;
if(c < t){
valid = false;
break;
}
}
if(valid){
ans = mid;
high = mid - 1;
}
else{
low = mid + 1;
}
}
cout<<ans<<'\n';
}
}
int main(){
ios_base::sync_with_stdio(false);
cin.tie(0);
int t = 1;
//cin>>t;
while(t--){
solve();
}
}
