#include <bits/stdc++.h>
using namespace std;
using ll = long long;
template <class t, class u>
void chmax(t& first, u second) {
  if (first < second) first = second;
}
template <class t, class u>
void chmin(t& first, u second) {
  if (second < first) first = second;
}
template <class t>
using vc = vector<t>;
template <class t>
using vvc = vc<vc<t>>;
using pi = pair<ll, ll>;
using vi = vc<ll>;
template <class t, class u>
ostream& operator<<(ostream& os, const pair<t, u>& p) {
  return os << "{" << p.first << "," << p.second << "}";
}
template <class t>
ostream& operator<<(ostream& os, const vc<t>& v) {
  os << "{";
  for (auto e : v) os << e << ",";
  return os << "}";
}
using uint = unsigned;
using ull = unsigned long long;
template <class t, size_t n>
ostream& operator<<(ostream& os, const array<t, n>& first) {
  return os << vc<t>(first.begin(), first.end());
}
template <ll i, class T>
void print_tuple(ostream&, const T&) {}
template <ll i, class T, class H, class... Args>
void print_tuple(ostream& os, const T& t) {
  if (i) os << ",";
  os << get<i>(t);
  print_tuple<i + 1, T, Args...>(os, t);
}
template <class... Args>
ostream& operator<<(ostream& os, const tuple<Args...>& t) {
  os << "{";
  print_tuple<0, tuple<Args...>, Args...>(os, t);
  return os << "}";
}
template <class t>
void print(t x, ll suc = 1) {
  cout << x;
  if (suc == 1) cout << "\n";
  if (suc == 2) cout << " ";
}
ll read() {
  ll i;
  cin >> i;
  return i;
}
vi readvi(ll n, ll off = 0) {
  vi v(n);
  for (ll i = ll(0); i < ll(n); i++) v[i] = read() + off;
  return v;
}
template <class T>
void print(const vector<T>& v, ll suc = 1) {
  for (ll i = ll(0); i < ll(v.size()); i++)
    print(v[i], i == ll(v.size()) - 1 ? suc : 2);
}
string readString() {
  string s;
  cin >> s;
  return s;
}
template <class T>
T sq(const T& t) {
  return t * t;
}
void yes(bool ex = true) {
  cout << "Yes"
       << "\n";
  if (ex) exit(0);
}
void no(bool ex = true) {
  cout << "No"
       << "\n";
  if (ex) exit(0);
}
void possible(bool ex = true) {
  cout << "Possible"
       << "\n";
  if (ex) exit(0);
}
void impossible(bool ex = true) {
  cout << "Impossible"
       << "\n";
  if (ex) exit(0);
}
constexpr ll ten(ll n) { return n == 0 ? 1 : ten(n - 1) * 10; }
const ll infLL = LLONG_MAX / 3;
const ll inf = infLL;
ll topbit(signed t) { return t == 0 ? -1 : 31 - __builtin_clz(t); }
ll topbit(ll t) { return t == 0 ? -1 : 63 - __builtin_clzll(t); }
ll botbit(signed first) { return first == 0 ? 32 : __builtin_ctz(first); }
ll botbit(ll first) { return first == 0 ? 64 : __builtin_ctzll(first); }
ll popcount(signed t) { return __builtin_popcount(t); }
ll popcount(ll t) { return __builtin_popcountll(t); }
bool ispow2(ll i) { return i && (i & -i) == i; }
ll mask(ll i) { return (ll(1) << i) - 1; }
bool inc(ll first, ll second, ll c) { return first <= second && second <= c; }
template <class t>
void mkuni(vc<t>& v) {
  sort(v.begin(), v.end());
  v.erase(unique(v.begin(), v.end()), v.end());
}
ll rand_int(ll l, ll r) {
  static mt19937_64 gen(chrono::steady_clock::now().time_since_epoch().count());
  return uniform_int_distribution<ll>(l, r)(gen);
}
template <class t>
void myshuffle(vc<t>& first) {
  for (ll i = ll(0); i < ll(ll(first.size())); i++)
    swap(first[i], first[rand_int(0, i)]);
}
template <class t>
ll lwb(const vc<t>& v, const t& first) {
  return lower_bound(v.begin(), v.end(), first) - v.begin();
}
struct unionfind {
  vi p, s;
  ll c;
  unionfind(ll n) : p(n, -1), s(n, 1), c(n) {}
  ll find(ll first) {
    return p[first] == -1 ? first : (p[first] = find(p[first]));
  }
  bool unite(ll first, ll second) {
    first = find(first);
    second = find(second);
    if (first == second) return false;
    p[second] = first;
    s[first] += s[second];
    c--;
    return true;
  }
  bool same(ll first, ll second) { return find(first) == find(second); }
  ll sz(ll first) { return s[find(first)]; }
};
struct E {
  ll first, second, c;
};
pair<ll, vi> mst(ll n, vc<E> es) {
  unionfind uf(n);
  vi idx(es.size());
  iota(idx.begin(), idx.end(), 0);
  sort(idx.begin(), idx.end(), [&](ll i, ll j) { return es[i].c < es[j].c; });
  ll ans = 0;
  vi used;
  for (auto i : idx)
    if (uf.unite(es[i].first, es[i].second)) {
      ans += es[i].c;
      used.push_back(i);
    }
  return {ans, used};
}
signed main() {
  cin.tie(0);
  ios::sync_with_stdio(0);
  cout << fixed << setprecision(20);
  vi r, g, second;
  {
    ll n;
    cin >> n;
    for (ll i = ll(0); i < ll(n); i++) {
      ll x;
      cin >> x;
      string s;
      cin >> s;
      if (s[0] == 'R')
        r.push_back(x);
      else if (s[0] == 'G')
        g.push_back(x);
      else
        second.push_back(x);
    }
  }
  if (ll(g.size()) == 0) {
    ll ans = 0;
    if (ll(r.size())) ans += r.back() - r.front();
    if (ll(second.size())) ans += second.back() - second.front();
    print(ans);
  } else {
    ll ans = g.back() - g.front();
    vi waf(ll(g.size()) - 1);
    for (auto z : {r, second}) {
      vc<pi> w;
      for (ll i = ll(0); i < ll(ll(g.size())); i++) w.emplace_back(g[i], i);
      ll n = ll(g.size());
      vc<E> es;
      for (ll i = ll(0); i < ll(n - 1); i++) es.push_back({i, i + 1, 0});
      for (ll i = ll(0); i < ll(ll(z.size())); i++) w.emplace_back(z[i], n + i);
      n += ll(z.size());
      sort(w.begin(), w.end());
      for (ll i = ll(0); i < ll(n - 1); i++)
        es.push_back(
            {w[i].second, w[i + 1].second, w[i + 1].first - w[i].first});
      auto res = mst(n, es);
      ans += res.first;
      vi non(n - 1, 1);
      for (auto i : res.second)
        if (i >= ll(g.size()) - 1) {
          i -= ll(g.size()) - 1;
          non[i] = 0;
        }
      vi cur(ll(g.size()) - 1, inf);
      for (ll i = ll(0); i < ll(n - 1); i++)
        if (non[i]) {
          ll p = w[i].first, q = w[i + 1].first;
          ll j = lwb(g, q);
          if (inc(1, j, ll(g.size()) - 1)) {
            j--;
            assert(cur[j] == inf);
            cur[j] = q - p;
          }
        }
      for (ll i = ll(0); i < ll(ll(g.size()) - 1); i++) waf[i] += cur[i];
    }
    for (ll i = ll(0); i < ll(ll(g.size()) - 1); i++) {
      ll len = g[i + 1] - g[i];
      ans += min(len, waf[i]) - len;
    }
    print(ans);
  }
}
