#include <iostream>
#include <vector>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <complex>
#include <cmath>
#include <map>
#include <set>
#include <string>
#include <queue>
#include <stack>
#include <bitset>
using namespace std;
#define pb(x) push_back(x)
#define ll long long
#define mk(x, y) make_pair(x, y)
#define lson l, m, rt<<1
#define mem(a) memset(a, 0, sizeof(a))
#define rson m+1, r, rt<<1|1
#define mem1(a) memset(a, -1, sizeof(a))
#define mem2(a) memset(a, 0x3f, sizeof(a))
#define rep(i, n, a) for(int i = a; i<n; i++)
#define fi first
#define se second
typedef complex <double> cmx;
typedef pair<int, int> pll;
const double PI = acos(-1.0);
const double eps = 1e-;
const int mod = 1e9+;
const int inf = ;
const int dir[][] = { {-, }, {, }, {, -}, {, } };
const int maxn = 1e5+;
int v[maxn*], n, b[maxn], cnt, num, sum[maxn*], ans[maxn];
struct node
{
int l, r, id, val;
}a[maxn];
bool cmp1(const node& lhs, const node& rhs)
{
return lhs.id < rhs.id;
}
bool cmp2(const node& lhs, const node& rhs)
{
if(lhs.r != rhs.r)
return lhs.r > rhs.r;
if(lhs.l != rhs.l)
return lhs.l < rhs.l;
return lhs.id < rhs.id;
}
int lowbit(int x) {return x&(-x);}
void update(int x, int val)
{
while(x <= cnt) {
sum[x] += val;
x += lowbit(x);
}
}
int query(int x)
{
int ret = ;
while(x) {
ret += sum[x];
x -= lowbit(x);
}
return ret;
}
void cdq(int l, int r)
{
if(l == r) return ;
int m = l+r>>;
cdq(l, m);
cdq(m+, r);
sort(a+l, a++r, cmp2);
for(int i = l; i <= r; i++) {
if(a[i].id <= m && a[i].val)
update(a[i].l, a[i].val);
if(a[i].id > m && !a[i].val)
ans[a[i].id] += query(a[i].l);
}
for(int i = l; i <= r; i++)
if(a[i].id <= m && a[i].val)
update(a[i].l, -a[i].val);
}
void solve()
{
mem(ans);
mem(sum);
sort(v, v+cnt);
cnt = unique(v, v+cnt)-v;
for(int i = ; i <= n; i++) {
a[i].l = lower_bound(v, v+cnt, a[i].l)-v+;
a[i].r = lower_bound(v, v+cnt, a[i].r)-v+;
}
cdq(, n);
sort(a+, a++n, cmp1);
for(int i = ; i <= n; i++) {
if(!a[i].val)
printf("%d\n", ans[i]);
}
}
int main()
{
int x;
while(~scanf("%d", &n)) {
cnt = num = ;
for(int i = ; i <= n; i++) {
char ch[];
scanf("%s", ch);
a[i].id = i;
if(ch[] == 'C') {
scanf("%d", &x);
a[i].l = a[b[x]].l;
a[i].r = a[b[x]].r;
a[i].val = -;
} else {
scanf("%d%d", &a[i].l, &a[i].r);
v[cnt++] = a[i].l;
v[cnt++] = a[i].r;
if(ch[] == 'D') {
b[++num] = i;
a[i].val = ;
} else {
a[i].val = ;
}
}
}
solve();
}
return ;
}
