#include <iostream>
#include <vector>
#include <cmath>
#include <algorithm>
#include <deque>
#include <map>
#include <queue>
#include <stack>
#include <set>
using namespace std;
using ll = long long int;
vector<char> v;
struct Node
{
int lcost, lsurplus, rcost, rsurplus;
};
vector<Node> segtree;
ll mod;
Node unite(Node a, Node b){ //left side a, right side b
Node ret;
ret.lcost = max(a.lcost + b.lcost - a.lsurplus, 0);
ret.lsurplus = max(a.lsurplus - a.lcost - b.lcost, 0) + b.lsurplus;
ret.rcost = max(a.rcost + b.rcost - b.rsurplus, 0);
ret.rsurplus = max(b.rsurplus - a.lcost - b.lcost, 0) + a.rsurplus;
return ret;
}
void build(int l, int r, int pos = 1){
if(l == r){
if(v[l] == 'C')
segtree[pos] = {0,1,0,1};
else{
segtree[pos] = {1, 0,1,0};
}
return;
}
int m = (l + r) / 2;
build(l, m, 2 * pos); build(m + 1, r, 2 * pos + 1);
segtree[pos] = unite(segtree[2 * pos], segtree[2 * pos + 1]);
}
Node query(int l, int r, int tl, int tr, int pos = 1){
if(tl == l && tr == r){
return segtree[pos];
}
int m = (tl + tr) / 2;
if(r <= m){
return query(l,r, tl, m, 2 * pos);
}
else if(l > m){
return query(l,r, m + 1, tr, 2 * pos + 1);
}
else{
return unite(query(l,m, tl, m, 2 * pos), query(m + 1,r, m + 1, tr, 2 * pos + 1));
}
}
int main()
{
ios::sync_with_stdio(false);
cin.tie(0);
int n, m;
cin >> n;
v.resize(n + 5,0);
segtree.resize(4 * n + 10);
for(int i = 1; i <= n; ++i){
cin >> v[i];
}
build(1, n);
cin >> m;
while(m--){
ll l, r;
cin >> l >> r;
Node ans= query(l,r, 1, n);
cout << max(ans.lcost, ans.rcost) << endl;
}
return 0;
}
/*ret.sol = a.sol + b.sol;
ret.sol = max({ret.sol - a.surplus, ret.sol - b.surplus, 0});
ret.surplus = min({a.surplus, b.surplus});
/*ret.surplus = a.surplus + b.surplus;
int prev = ret.sol;
ret.sol = max(ret.sol - ret.surplus, 0);
ret.surplus -= prev - ret.sol;*/
