#include<bits/stdc++.h>
using namespace std;
using ll = long long int;
using ld = long double;
#define pow(n,m) powl(n,m)
#define sqrt(n) sqrtl(n)
const ll MAX = 5000000000000000000;
const ll MOD = 0;
void randinit(){srand((unsigned)time(NULL));}
int main(){
    ll N;
    cin >> N;
    N *= 2;
    vector<ll> A,B,C;
    for(ll i = 0;i < N;i++){
        ll a;
        char c;
        cin >> a >> c;
        if(c == 'R') A.emplace_back(a);
        if(c == 'G') B.emplace_back(a);
        if(c == 'B') C.emplace_back(a);
    }
    sort(A.begin(),A.end());
    sort(B.begin(),B.end());
    sort(C.begin(),C.end());
    if(A.size() % 2 == 0 && B.size() % 2 == 0 && C.size() % 2 == 0){
        cout << 0 << endl;
        return 0;
    }
    ll a,b,c;
    if(A.size() == 0) a = 0;
    else a = 2 - (A.size() % 2);
    if(B.size() == 0) b = 0;
    else b = 2 - (B.size() % 2);
    if(C.size() == 0) c = 0;
    else c = 2 - (C.size() % 2);
    if(a > b){
        swap(a,b);
        swap(A,B);
    }
    if(b > c){
        swap(b,c);
        swap(B,C);
    }
    if(a > b){
        swap(a,b);
        swap(A,B);
    }
    if(b > c){
        swap(b,c);
        swap(B,C);
    }
    if(a > b){
        swap(a,b);
        swap(A,B);
    }
    if(b > c){
        swap(b,c);
        swap(B,C);
    }
    ll ans = MAX;
    if(a == 0){
        swap(a,c);
        swap(A,C);
    }
    vector<ll> AA = A,BB = B;
    BB.emplace_back(-MAX);
    BB.emplace_back(MAX);
    sort(BB.begin(),BB.end());
    for(ll i = 0;i < A.size();i++){
        ans = min(ans,abs(A[i] - *(lower_bound(BB.begin(),BB.end(),A[i]))));
        ans = min(ans,abs(A[i] - *(upper_bound(BB.begin(),BB.end(),A[i]) - 1)));
    }
    if(c != 0){
        vector<ll> AAA = A,BBB = B,CCC = C;
        AAA.emplace_back(-MAX);
        AAA.emplace_back(MAX);
        sort(AAA.begin(),AAA.end());
        BBB.emplace_back(-MAX);
        BBB.emplace_back(MAX);
        sort(BBB.begin(),BBB.end());
        vector<ll> P;
        for(ll i = 0;i < C.size();i++){
            ll p = min(
                abs(C[i] - *(lower_bound(AAA.begin(),AAA.end(),C[i]))),
                abs(C[i] - *(upper_bound(AAA.begin(),AAA.end(),C[i]) - 1))
            );
            P.emplace_back(p);
        }
        vector<ll> PP = P;
        sort(PP.begin(),PP.end());
        for(ll i = 0;i < C.size();i++){
            ll p = min(
                abs(C[i] - *(lower_bound(BBB.begin(),BBB.end(),C[i]))),
                abs(C[i] - *(upper_bound(BBB.begin(),BBB.end(),C[i]) - 1))
            );
            if(PP[0] == PP[1] || PP[0] != P[i]){
                ans = min(ans,p + PP[0]);
            }
            else{
                ans = min(ans,p + PP[1]);
            }
        }
    }
    cout << ans << endl;
}

#include <bits/stdc++.h>
#define fi first
#define se second
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define rrep(i,n) for(int i = 1; i <= (n); ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
#define srep(i,s,t) for (int i = s; i < (t); ++i)
#define dsrep(i,t,s) for(int i = (t)-1; i >= (s); --i)
#define rng(a) a.begin(),a.end()
#define rrng(a) a.rbegin(),a.rend()
#define isin(x,l,r) ((l) <= (x) && (x) < (r))
#define pb push_back
#define eb emplace_back
#define sz(x) (int)(x).size()
#define pcnt __builtin_popcountll
#define snuke srand((unsigned)clock()+(unsigned)time(NULL));
#define show(x) cerr<<#x<<" = "<<x<<endl;
#define bn(x) ((1<<(x))-1)
#define newline puts("")
using namespace std;
template<typename T> using vc = vector<T>;
template<typename T> using vv = vc<vc<T>>;
template<typename T> using PQ = priority_queue<T,vc<T>,greater<T> >;
using ll = long long;
using uint = unsigned;
using ull = unsigned long long;
using P = pair<ll,int>;
using T3 = tuple<int,int,int>;
using vi = vc<int>;
using vvi = vv<int>;
using vl = vc<ll>;
using vp = vc<P>;
using vt = vc<T3>;
int getInt(){int x;scanf("%d",&x);return x;}
vi pm(int n, int s=0) { vi a(n); iota(rng(a),s); return a;}
template<typename T>istream& operator>>(istream&i,vc<T>&v){rep(j,sz(v))i>>v[j];return i;}
template<typename T>string join(const T&v,const string& d=""){stringstream s;rep(i,sz(v))(i?s<<d:s)<<v[i];return s.str();}
template<typename T>ostream& operator<<(ostream&o,const vc<T>&v){if(sz(v))o<<join(v," ");return o;}
template<typename T1,typename T2>istream& operator>>(istream&i,pair<T1,T2>&v){return i>>v.fi>>v.se;}
template<typename T1,typename T2>ostream& operator<<(ostream&o,const pair<T1,T2>&v){return o<<v.fi<<","<<v.se;}
vc<string> split(const string& s,char d=' '){vc<string> r(1);for(char c:s)if(c==d)r.pb("");else r.back()+=c;return r;}
string operator*(const string& s,int t){return join(vc<string>(t,s));}
template<typename T1,typename T2>bool mins(T1& x,const T2&y){if(x>y){x=y;return true;}else return false;}
template<typename T1,typename T2>bool maxs(T1& x,const T2&y){if(x<y){x=y;return true;}else return false;}
template<typename T>T dup(T x, T y){return (x+y-1)/y;}
template<typename T>ll suma(const vc<T>&a){ll res(0);for(auto&&x:a)res+=x;return res;}
template<typename T>void uni(T& a){sort(rng(a));a.erase(unique(rng(a)),a.end());}
const double eps = 1e-10;
const ll LINF = 1001002003004005006ll;
const int INF = 1001001001;
#define dame { puts("-1"); return;}
#define yn {puts("Yes");}else{puts("No");}
const int MX = 200005;
using vvl = vc<vl>;

struct Solver {
  void solve() {
    int n;
    scanf("%d",&n);
    vvl a(3);
    vp p;
    rep(i,n*2) {
      char c;
      ll x;
      scanf("%lld %c",&x,&c);
      c %= 3;
      a[c].pb(x);
      p.eb(x,c);
    }
    sort(rng(p));
    vl dp(16, LINF);
    dp[0] = 0;
    for (auto x : p) {
      vl pd(16,LINF); swap(dp,pd);
      rep(i,16) {
        mins(dp[i^1<<x.se], pd[i]);
        ll now = -x.fi;
        if (i&8) now = -now;
        mins(dp[i^8], pd[i]+now);
      }
    }
    ll ans = dp[0];

    // vi os;
    // rep(i,3) {
    //   sort(rng(a[i]));
    //   if (sz(a[i])&1) os.pb(i);
    // }
    // ll ans = 0;
    // if (sz(os)) {
    //   ans = LINF;
    //   vl x = a[os[0]];
    //   vl y = a[os[1]];
    //   int xi = 0, yi = 0;
    //   while (xi < sz(x) && yi < sz(y)) {
    //     mins(ans, abs(x[xi]-y[yi]));
    //     if (x[xi] < y[yi]) ++xi; else ++yi;
    //   }
    // }
    cout<<ans<<endl;
  }
};

int main() {
  int ts = 1;
  // scanf("%d",&ts);
  rrep(ti,ts) {
    Solver solver;
    solver.solve();
  }
  return 0;
}
