#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#include <utility>
#include <algorithm>
struct SegTreeNode {
int sum = 0;
int max_pfx = -0x3f3f3f3f;
int max_sfx = -0x3f3f3f3f;
int max = 0;
};
SegTreeNode combine(const SegTreeNode& a, const SegTreeNode& b) {
SegTreeNode ret;
ret.sum = a.sum + b.sum;
ret.max_pfx = std::max(a.max_pfx, a.sum + b.max_pfx);
ret.max_sfx = std::max(b.max_sfx, b.sum + a.max_sfx);
ret.max = std::max({0, a.max + b.sum, b.max + a.sum, a.max_pfx + b.max_sfx});
return ret;
}
int x, q;
std::string str;
SegTreeNode tree[2000005];
void build_tree(int node, int l, int r) {
if (l==r) {
tree[node].sum = ((str[l]=='C') ? -1 : 1);
tree[node].max_pfx = tree[node].max_sfx = tree[node].sum;
tree[node].max = std::max(0, tree[node].sum);
return;
}
int m = (l+r)>>1;
build_tree(node<<1,l,m);
build_tree(node<<1|1,m+1,r);
tree[node] = combine(tree[node<<1],tree[node<<1|1]);
}
SegTreeNode query(int node, int l, int r, int st, int fi) {
if (l>fi||r<st) {
SegTreeNode ret;
return ret;
}
if (st<=l&&r<=fi) {
return tree[node];
}
int m = (l+r)>>1;
return combine(query(node<<1,l,m,st,fi),query(node<<1|1,m+1,r,st,fi));
}
int main() {
std::ios_base::sync_with_stdio(false);
std::cin.tie(NULL);
std::cout.tie(NULL);
std::cin >> x >> str;
build_tree(1,0,x-1);
std::cin >> q;
while (q--) {
int l, r;
std::cin >> l >> r; --l, --r;
SegTreeNode ret = query(1,0,x-1,l,r);
//std::cout << ret.sum << " " << ret.max_pfx << " " << ret.max_sfx << " " << ret.max << "\n";
std::cout << query(1,0,x-1,l,r).max << "\n";
}
}
