#pragma region header
#include <bits/stdc++.h>
#define int long long
#define all(a) begin(a), end(a)
#define rall(a) rbegin(a), rend(a)
#define mp make_pair
#define rep1(i, n) for (decltype(+n) i = 0; i < (n); i++)
#define rrep1(i, n) for (auto i = n - 1; i > static_cast<decltype(i)>(-1); i--)
#define rep2(i, a, b) for (auto i = (a); i < (b); i++)
#define rrep2(i, a, b) for (auto i = b - 1; i >= a; i--)
#define GET_MACRO(_1, _2, _3, NAME, ...) NAME
#define rep(...) GET_MACRO(__VA_ARGS__, rep2, rep1) (__VA_ARGS__)
#define rrep(...) GET_MACRO(__VA_ARGS__, rrep2, rrep1) (__VA_ARGS__)
#define each(i, a) for (auto &&i : (a))
using namespace std;

using ld = long double;
using vi = vector<int>;
using vvi = vector<vi>;
using vs = vector<string>;
using vvs = vector<vs>;
using vd = vector<ld>;
using vvd = vector<vd>;
using vb = vector<bool>;
using vvb = vector<vb>;
using pii = pair<int, int>;
using vp = vector<pii>;
using vvp = vector<vp>;
using mii = map<int, int>;
using vm = vector<mii>;
using vvm = vector<vm>;
template <class T, class U>
using umap = unordered_map<T, U>;
using umii = umap<int, int>;
using seti = set<int>;
template <class T>
using uset = unordered_set<T>;
using useti = uset<int>;
template <class T>
using less_queue = priority_queue<T>;
template <class T>
using greater_queue = priority_queue<T, vector<T>, greater<T>>;

constexpr int INF = 1e18;

template <class T>
void SORT(T &a) { stable_sort(all(a)); }
template <class T>
void RSORT(T &a) { stable_sort(rall(a)); }
template <class T>
void rev(T &a) { reverse(rall(a)); }
template <class T>
void uniq(T &a) { a.erase(unique(all(a)), end(a)); }
template <class T>
auto min_of(T a) { return *min_element(all(a)); }
template <class T>
auto max_of(T a) { return *max_element(all(a)); }
template <class T>
int sum_of(T a) { return accumulate(all(a), 0ll); }
template <class T, class U>
auto sum_of(T a, U init) { return accumulate(all(a), init); }
template <class T, class U>
int count_of(T a, U i) { return count(all(a), i); }
template <class T, class U>
bool has(T a, U i) { return find(all(a), i) != end(a); }
template <class T>
int sz(T a) { return a.size(); };

template <class T>
void COUT(T x) { cout << x << endl; }
template <class T, class U>
void COUT(T x, U y) { cout << x << ' ' << y << endl; }
template <class T, class U, class V>
void COUT(T x, U y, V z) { cout << x << ' ' << y << ' ' << z << endl; }
template <class T>
void CSP(T x) { cout << x << ' '; }
template <class T>
void CVEC(T v) {
  int c = v.size() - 1;
  for (int i = 0; i < c; i++) cout << v[i] << ' ';
  if (c > -1) cout << v[c];
  cout << endl;
}

template <class T>
bool amin(T &a, const T &b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
template <class T>
bool amax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}

constexpr int lshift(int x) noexcept { return 1ll << x; }
constexpr int popcount(unsigned int x) noexcept { return __builtin_popcountll(x); }
constexpr int least1(unsigned int x) noexcept { return __builtin_ffsll(x); }
constexpr int ceil_div(int x, int y) noexcept { return (x - 1) / y + 1; }

#pragma endregion header

template<typename T>
struct edge {
  int to;
  T cost;
  edge(int to, T cost) : to(to), cost(cost) {}
};
template<typename T>
vector<T> dijkstra(vector<vector<edge<T>>> &g, int s, const T &INF) {
  vector<T> dist(g.size(), INF);
  priority_queue<pair<T, int>> pq;
  dist[s] = 0;
  pq.emplace(dist[s], s);
  while(!pq.empty()) {
    T cost;
    int idx;
    tie(cost, idx) = pq.top();
    pq.pop();
    if(dist[idx] < cost) continue;
    for(auto &e : g[idx]) {
      auto next_cost = cost + e.cost;
      if(dist[e.to] <= next_cost) continue;
      dist[e.to] = next_cost;
      pq.emplace(dist[e.to], e.to);
    }
  }
  return dist;
}

string revstr(string s) {
  string t = s;
  rev(t);
  return t;
}

void solve(int n, vector<string> s, vi c) {
  rep(i, n) {
    s.push_back(revstr(s[i]));
    c.push_back(c[i]);
  }
  vvi id(n * 2);
  int m = 1;
  rep(i, n * 2)each(_, s[i])id[i].push_back(m++);
  vector<vector<edge<int>>> g(m);
  rep(i, n * 2) {
    int sl = sz(s[i]);
    bool r = i / n;
    rep(li, sl) {
      int il = sl - li, iid = id[i][li];
      string is = s[i].substr(li, il);
      if(is == revstr(is)) {
        g[iid].emplace_back(0, 0);
        continue;
      }
      rep(j, n) {
        int jj = r ? j : j + n;
        string js = s[jj];
        int jl = sz(js);
        bool same = true;
        rep(k, min(il, jl))if(is[k] != js[k])same = false;
        if(!same)continue;
        if(il == jl) g[iid].emplace_back(0, c[jj]);
        else if(il < jl) g[iid].emplace_back(id[jj][il], c[jj]);
        else g[iid].emplace_back(id[i][li + jl], c[jj]);
      }
    }
  }
  int ans = INF;
  rep(i, n * 2) {
    vi dij = dijkstra(g, id[i][0], INF);
    amin(ans, dij[0] + c[i]);
  }
  COUT(ans == INF ? -1 : ans);
}


#pragma region main
signed main() {
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  cout << fixed << setprecision(15);

  int n;
  cin >> n;
  vector<string> s(n);
  vi c(n);
  for(int i = 0 ; i < n ; i++){
    cin >> s[i];
    cin >> c[i];
  }
  solve(n, move(s), move(c));
}
#pragma endregion main


Measured memory_bytes: 3752