#include <bits/stdc++.h>
#define int long long
using namespace std;
const int MAX_N = 5e5;
const int MOD = 1e9 + 7;
const int INF = 1e9;
struct Node {
int L, R, A, S;
};
string s;
Node segm[4*MAX_N];
Node comb(Node a, Node b) {
Node c;
c.S = a.S + b.S;
c.L = max(a.L, a.S + b.L);
c.R = max(b.R, b.S + a.R);
c.A = max(max(a.S + b.A, b.S + a.A), a.L + b.R);
return c;
}
void build(int pos, int l, int r) {
if(l==r) {
if(s[l] == 'C') {
segm[pos].S = -1;
segm[pos].L = segm[pos].R = segm[pos].A = 0;
} else {
segm[pos].S = segm[pos].R = segm[pos].L = segm[pos].A = 1;
}
return;
}
int m = (l+r)/2;
build(2*pos+1, l, m);
build(2*pos+2, m+1, r);
segm[pos] = comb(segm[2*pos+1], segm[2*pos+2]);
}
Node query(int pos, int l, int r, int L, int R) {
if(l > R or r < L) {
Node tmp;
tmp.A = tmp.L = tmp.R = tmp.S = 0;
return tmp;
} else if(l >= L && r <= R) return segm[pos];
int m = (l+r)/2;
return comb(query(2*pos+1, l, m, L, R), query(2*pos+2, m+1, r, L, R));
}
void solve() {
int n, q;
cin >> n >> s >> q;
build(1, 0, n-1);
while(q--) {
int l, r;
cin >> l >> r;
--l, --r;
Node ans = query(1, 0, n-1, l, r);
cout << ans.A << endl;
}
}
signed main()
{
ios_base::sync_with_stdio(false);
cin.tie(0); cout.tie(0);
int t = 1;
while(t--) solve();
return 0;
}
