#include "bits/stdc++.h"
#define MAXN 500009
#define INF 1000000007
#define mp(x,y) make_pair(x,y)
#define all(v) v.begin(),v.end()
#define pb(x) push_back(x)
#define wr cout<<"----------------"<<endl;
#define ppb() pop_back()
#define tr(ii,c) for(__typeof((c).begin()) ii=(c).begin();ii!=(c).end();ii++)
#define ff first
#define ss second
#define my_little_dodge 46
#define debug(x) cerr<< #x <<" = "<< x<<endl;
using namespace std;
typedef long long ll;
typedef pair<int,int> PII;
template<class T>bool umin(T& a,T b){if(a>b){a=b;return 1;}return 0;}
template<class T>bool umax(T& a,T b){if(a<b){a=b;return 1;}return 0;}
char sa[MAXN];
int suf[MAXN],pre[MAXN],dp[MAXN*2];
vector<PII>query[MAXN];
vector<int>adj[MAXN];
int s[MAXN<<2],lazy[MAXN<<2],ans[MAXN],n;
void build(int nd,int x,int y){
if(x==y){
s[nd]=suf[x];
return;
}
int mid=(x+y)>>1;
build(nd<<1,x,mid);
build(nd<<1|1,mid+1,y);
s[nd]=min(s[nd<<1],s[nd<<1|1]);
}
void shift(int nd){
int &ret=lazy[nd];
if(!ret)
return;
lazy[nd<<1]+=ret;s[nd<<1]+=ret;
lazy[nd<<1|1]+=ret;s[nd<<1|1]+=ret;
ret=0;
}
void inc(int l,int r,int v,int nd,int x,int y){
if(l>y or x>r)
return;
if(l<=x and y<=r){
s[nd]+=v;
lazy[nd]+=v;
return;
}
shift(nd);
int mid=(x+y)>>1;
inc(l,r,v,nd<<1,x,mid);
inc(l,r,v,nd<<1|1,mid+1,y);
s[nd]=min(s[nd<<1],s[nd<<1|1]);
}
int tap(int l,int r,int nd,int x,int y){
if(l>y or x>r)
return INF;
if(l<=x and y<=r)
return s[nd];
shift(nd);
int mid=(x+y)>>1;
return min(tap(l,r,nd<<1,x,mid),tap(l,r,nd<<1|1,mid+1,y));
}
int P[MAXN][19];
int get(int x,int y){
int res=0;
for(int i=18;i>=0;i--)
if(~P[x][i] and P[x][i]<=y)
x=P[x][i],res+=(1<<i);
return res;
}
void dfs(int nd){
tr(it,query[nd+1]){
int r=it->ff,ind=it->ss;
if(r==n)
ans[ind]=max(0,-tap(nd+1,r,1,1,n));
else
ans[ind]=max(0,-tap(nd+1,r,1,1,n)+tap(r+1,r+1,1,1,n));
ans[ind]+=get(nd,r);
}
inc(1,nd,+1,1,1,n);
for(int i=0;i<int(adj[nd].size());i++){
int to=adj[nd][i];
dfs(to);
}
inc(1,nd,-1,1,1,n);
}
int main(){
memset(P,-1,sizeof P);
//~ freopen("file.in", "r", stdin);
scanf("%d",&n);
scanf("%s",sa+1);
for(int i=1;i<=n;i++){
pre[i]=pre[i-1];
if(sa[i]=='C')
pre[i]++;
else
pre[i]--;
}
for(int i=n;i>=1;i--){
suf[i]=suf[i+1];
if(sa[i]=='C')
suf[i]++;
else
suf[i]--;
}
vector<int>root;
memset(dp,-1,sizeof dp);
for(int i=n;i>=0;i--){
if(~dp[pre[i]+n-1]){
adj[dp[pre[i]+n-1]].pb(i);
P[i][0]=dp[pre[i]+n-1];
for(int j=1;j<=18;j++)
if(~P[i][j-1])
P[i][j]=P[P[i][j-1]][j-1];
}
else
root.pb(i);
dp[pre[i]+n]=i;
}
build(1,1,n);
int q;
scanf("%d",&q);
for(int i=1;i<=q;i++){
int l,r;
scanf("%d%d",&l,&r);
query[l].pb(mp(r,i));
}
tr(it,root)
dfs(*it);
for(int i=1;i<=q;i++)
printf("%d\n",ans[i]);
//~ int q;
//~ scanf("%d",&q);
//~ while(q--){
//~ int l,r;
//~ scanf("%d%d",&l,&r);
//~ int last=l-1;
//~ for(int i=l;i<=r;i++)
//~ if(par[i]==par[last]-1){
//~ last=i;
//~ vis[i]=1;
//~ }
//~ int sum=0,mn=INF;
//~ for(int i=r;i>=l;i--)
//~ if(!vis[i]){
//~ sum+=(s[i]=='C');
//~ sum-=(s[i]=='T');
//~ umin(mn,sum);
//~ }
//~ int ans=0;
//~ for(int i=l;i<=r;i++){
//~ ans+=vis[i];
//~ vis[i]=0;
//~ }
//~ printf("%d\n",ans+max(0,-mn));
//~ }
return 0;
}
