#include <bits/stdc++.h>
#include <vector>
using namespace std;
#define ll long long
#define ull unsigned long long
#define ld long double
#define ff first
#define ss second
#define ln "\n"
#define mp make_pair
const ll INF = 2e18;
const ll MOD = 998244353;
struct SegTree{
struct node{
ll pref, suff, sum, res;
};
vector<node> t;
ll sz, rsz;
SegTree(ll N){
sz=N*4; rsz=N;
t.resize(sz);
}
node merge(node l, node r){
node nw;
nw.pref = min({l.pref, l.sum+r.pref, 0ll});
nw.suff = min({r.suff, r.sum+l.suff, 0ll});
nw.sum = l.sum+r.sum;
nw.res = min({l.sum+r.res, r.sum+l.res, l.pref+r.suff, 0ll});
return nw;
}
void build(ll tl, ll tr, ll v, string &s){
if (tl==tr){
t[v].sum = {s[tl]=='C'?1:-1};
t[v].pref=t[v].suff=t[v].res=min(0ll, t[v].sum);
}else{
ll tm = (tl+tr)/2;
build(tl, tm, v*2, s);
build(tm+1, tr, v*2+1, s);
t[v] = merge(t[v*2], t[v*2+1]);
}
}
node query(ll tl, ll tr, ll v, ll l, ll r){
if (tl==l and tr==r){
return t[v];
}else if (l>r) return {0, 0, 0, 0};
else{
ll tm = (tl+tr)/2;
return merge(query(tl, tm, v*2, l, min(r, tm)), query(tm+1, tr, v*2+1, max(l, tm+1), r));
}
}
ll query(ll l, ll r){
return abs(query(0, rsz-1, 1, l, r).res);
}
void build(string &s){
build(0, rsz-1, 1, s);
}
};
void solve(){
ll n; cin >> n;
string s; cin >> s;
SegTree tr(n); tr.build(s);
ll q; cin >> q;
while (q--){
ll l, r; cin >> l >> r; l--; r--;
cout << tr.query(l, r) << ln;
}
}
int main(){
ios_base::sync_with_stdio(false); cin.tie(nullptr);
auto start = chrono::high_resolution_clock::now();
ll t=1;
// cin >> t;
while (t--) solve();
#ifdef LOCAL
auto duration = chrono::duration_cast<chrono::microseconds>(chrono::high_resolution_clock::now() - start);
cout << setprecision(0) << fixed << "time: " << (double)duration.count()/1000.0 << " milliseconds" << endl;
#endif
}
