#include <bits/stdc++.h>
using namespace std;
template <typename... As>
struct tpl : public std::tuple<As...> {
  using std::tuple<As...>::tuple;
  tpl() {}
  tpl(std::tuple<As...> const& b) { std::tuple<As...>::operator=(b); }
  template <typename T = tuple<As...> >
  typename tuple_element<0, T>::type const& x() const {
    return get<0>(*this);
  }
  template <typename T = tuple<As...> >
  typename tuple_element<0, T>::type& x() {
    return get<0>(*this);
  }
  template <typename T = tuple<As...> >
  typename tuple_element<1, T>::type const& y() const {
    return get<1>(*this);
  }
  template <typename T = tuple<As...> >
  typename tuple_element<1, T>::type& y() {
    return get<1>(*this);
  }
  template <typename T = tuple<As...> >
  typename tuple_element<2, T>::type const& z() const {
    return get<2>(*this);
  }
  template <typename T = tuple<As...> >
  typename tuple_element<2, T>::type& z() {
    return get<2>(*this);
  }
  template <typename T = tuple<As...> >
  typename tuple_element<3, T>::type const& w() const {
    return get<3>(*this);
  }
  template <typename T = tuple<As...> >
  typename tuple_element<3, T>::type& w() {
    return get<3>(*this);
  }
};
using lli = long long int;
using llu = long long unsigned;
using pii = tpl<lli, lli>;
using piii = tpl<lli, lli, lli>;
using piiii = tpl<lli, lli, lli, lli>;
using vi = vector<lli>;
using vii = vector<pii>;
using viii = vector<piii>;
using vvi = vector<vi>;
using vvii = vector<vii>;
using vviii = vector<viii>;
template <class T>
using min_queue = priority_queue<T, vector<T>, greater<T> >;
template <class T>
using max_queue = priority_queue<T>;
template <size_t... I>
struct my_index_sequence {
  using type = my_index_sequence;
  static constexpr array<size_t, sizeof...(I)> value = {{I...}};
};
namespace my_index_sequence_detail {
template <typename I, typename J>
struct concat;
template <size_t... I, size_t... J>
struct concat<my_index_sequence<I...>, my_index_sequence<J...> >
    : my_index_sequence<I..., (sizeof...(I) + J)...> {};
template <size_t N>
struct make_index_sequence
    : concat<typename make_index_sequence<N / 2>::type,
             typename make_index_sequence<N - N / 2>::type>::type {};
template <>
struct make_index_sequence<0> : my_index_sequence<> {};
template <>
struct make_index_sequence<1> : my_index_sequence<0> {};
}  // namespace my_index_sequence_detail
template <class... A>
using my_index_sequence_for =
    typename my_index_sequence_detail::make_index_sequence<sizeof...(A)>::type;
template <class T, size_t... I>
void print_tuple(ostream& s, T const& a, my_index_sequence<I...>) {
  using swallow = int[];
  (void)swallow{0, (void(s << (I == 0 ? "" : ", ") << get<I>(a)), 0)...};
}
template <class T>
ostream& print_collection(ostream& s, T const& a);
template <class... A>
ostream& operator<<(ostream& s, tpl<A...> const& a);
template <class... A>
ostream& operator<<(ostream& s, tuple<A...> const& a);
template <class A, class B>
ostream& operator<<(ostream& s, pair<A, B> const& a);
template <class T, size_t I>
ostream& operator<<(ostream& s, array<T, I> const& a) {
  return print_collection(s, a);
}
template <class T>
ostream& operator<<(ostream& s, vector<T> const& a) {
  return print_collection(s, a);
}
template <class T, class U>
ostream& operator<<(ostream& s, multimap<T, U> const& a) {
  return print_collection(s, a);
}
template <class T>
ostream& operator<<(ostream& s, multiset<T> const& a) {
  return print_collection(s, a);
}
template <class T, class U>
ostream& operator<<(ostream& s, map<T, U> const& a) {
  return print_collection(s, a);
}
template <class T>
ostream& operator<<(ostream& s, set<T> const& a) {
  return print_collection(s, a);
}
template <class T>
ostream& print_collection(ostream& s, T const& a) {
  s << '[';
  for (auto it = begin(a); it != end(a); ++it) {
    s << *it;
    if (it != prev(end(a))) s << " ";
  }
  return s << ']';
}
template <class... A>
ostream& operator<<(ostream& s, tpl<A...> const& a) {
  s << '(';
  print_tuple(s, a, my_index_sequence_for<A...>{});
  return s << ')';
}
template <class... A>
ostream& operator<<(ostream& s, tuple<A...> const& a) {
  s << '(';
  print_tuple(s, a, my_index_sequence_for<A...>{});
  return s << ')';
}
template <class A, class B>
ostream& operator<<(ostream& s, pair<A, B> const& a) {
  return s << "(" << get<0>(a) << ", " << get<1>(a) << ")";
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  int n;
  cin >> n;
  deque<lli> curR, curB;
  int lastG = -1;
  lli ans = 0;
  for (lli i = 0; i < (lli)(n); ++i) {
    lli x;
    cin >> x;
    char c;
    cin >> c;
    if (c == 'G') {
      if (lastG != -1) {
        curR.push_front(lastG);
        curR.push_back(x);
        curB.push_front(lastG);
        curB.push_back(x);
        vi dr, db;
        for (lli i = 0; i < (lli)(curR.size() - 1); ++i)
          dr.push_back(curR[i + 1] - curR[i]);
        for (lli i = 0; i < (lli)(curB.size() - 1); ++i)
          db.push_back(curB[i + 1] - curB[i]);
        sort(begin(dr), end(dr));
        sort(begin(db), end(db));
        dr.pop_back();
        db.pop_back();
        ans +=
            min(2 * (x - lastG), x - lastG + accumulate(begin(dr), end(dr), 0) +
                                     accumulate(begin(db), end(db), 0));
      } else {
        if (!curR.empty()) ans += x - curR[0];
        if (!curB.empty()) ans += x - curB[0];
      }
      lastG = x;
      curR.clear();
      curB.clear();
    } else if (c == 'R') {
      curR.push_back(x);
    } else {
      curB.push_back(x);
    }
  }
  if (lastG == -1) {
    if (!curR.empty()) ans += curR.back() - curR[0];
    if (!curB.empty()) ans += curB.back() - curB[0];
  } else {
    if (!curR.empty()) ans += curR.back() - lastG;
    if (!curB.empty()) ans += curB.back() - lastG;
  }
  cout << ans << endl;
  return 0;
}
