#include<bits/stdc++.h>
using namespace std;

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;

template <typename T> using oset = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

// macros
#define int long long 
#define ll long long 
#define ld long double
#define TIME clock() * 1.0 / CLOCKS_PER_SEC
#define sz(x) ((int)((x).size()))

template <typename A, typename B>
string to_string(pair<A, B> p);
 
template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p);
 
template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p);

string to_string(const string& s) {
  return '"' + s + '"';
}

string to_string(const char& s) {
  return to_string(string(1, s));
}
 
string to_string(const char* s) {
  return to_string((string) s);
}
 
string to_string(bool b) {
  return (b ? "1" : "0");
}
 
string to_string(vector<bool> v) {
	bool first = true;
	string res = "{";
	for (int i = 0; i < static_cast<int>(v.size()); i++) {
		if (!first) {
			res += ", ";
		}
		first = false;
		res += to_string(v[i]);
	}
	res += "}";
	return res;
}
 
template <size_t N>
string to_string(bitset<N> v) {
	string res = "";
	for (size_t i = 0; i < N; i++) {
		res += static_cast<char>('0' + v[i]);
	}
	return res;
}
 
template <typename A>
string to_string(A v) {
	bool first = true;
	string res = "{";
	for (const auto &x : v) {
		if (!first) {
			res += ", ";
		}
		first = false;
		res += to_string(x);
	}
	res += "}";
	return res;
}
 
template <typename A, typename B>
string to_string(pair<A, B> p) {
	return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}
 
template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p) {
	return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " + to_string(get<2>(p)) + ")";
}
 
template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p) {
    return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " + to_string(get<2>(p)) + ", " + to_string(get<3>(p)) + ")";
}
 
void debug_out() { cerr << endl; }
 
template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
  cerr << " " << to_string(H);
  debug_out(T...);
}
 
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)

template <typename T1, typename T2>
inline auto mini(T1 a, T2 b) { return (a < b ? a : b); }
template<typename T, typename... Args>
inline auto mini(T a, Args... args) { return mini(a, mini(args...)); }
template <typename T1, typename T2>
inline auto maxi(T1 a, T2 b) { return (a > b ? a : b); }
template<typename T, typename... Args>
inline auto maxi(T a, Args... args) { return maxi(a, maxi(args...)); }
template<typename T>
T gcd(T a, T b) { if(a==0 or b==0) return a+b; return gcd(b, a%b) ; }
template<typename T>
T lcm(T a, T b) { if(a==0 or b==0) return 0; return a/gcd(a, b)*b; }

// random number generator
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count()); // use mt19937_64 for 64 bit

// constants
const long double eps = LDBL_EPSILON;
const int inf = 1e15;
const int modn = 1e9+7;
const int maxn = 2e5+3;

bool check_pd(string &s) {
	string srev = s;
	reverse(srev.begin(), srev.end());
	return s == srev;
}

bool check(string& s1, string& s2) {
	int i1 = 0, i2 = 0;
	while(i1 < sz(s1) and i2 < sz(s2)) {
		if(s1[i1] != s2[sz(s2) - 1 - i2]) return false;
		i1++;
		i2++;
	}
	return true;
}

int32_t main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    // Your code here
	int n;
	cin >> n;
	vector<string> a(n);
	vector<int> cost(n);
	for(int i = 0; i < n; i++) {
		cin >> a[i] >> cost[i];
	}
	int ans = inf;
	int res = 0;
	function<void(string, int)> solve = [&](string s, int pref) {
		if(sz(s) == 0) return;
		if(check_pd(s)) {
			ans = min(ans, res);
			return;
		}
		for(int i = 0; i < n; i++) {
			string tmp = s + a[i];
			if(check_pd(tmp)) {
				ans = min(ans, res + cost[i]);
				return;
			}
			if(pref) {
				if(!check(s, a[i])) continue;
				if(sz(s) == sz(a[i])) {
					ans = min(ans, res + cost[i]);
					return;
				}
				if(sz(s) > sz(a[i])) {
					string snext;
					for(int j = 0; j < sz(s); j++) {
						if(j < sz(a[i])) continue;
						snext += s[j];
					}
					res += cost[i];
					solve(snext, 1);
					res -= cost[i];
				}
				else {
					string snext;
					for(int j = 0; j < sz(a[i]) - sz(s); j++) {
						snext += a[i][j];
					}
					res += cost[i];
					solve(snext, 0);
					res -= cost[i];
				}
			}
			else {
				if(!check(a[i], s)) continue;
				if(sz(a[i]) == sz(s)) {
					ans = min(ans, res + cost[i]);
					return;
				}
				if(sz(a[i]) > sz(s)) {
					string snext;
					for(int j = 0; j < sz(a[i]); j++) {
						if(j < sz(s)) continue;
						snext += a[i][j];
					}
					res += cost[i];
					solve(snext, 1);
					res -= cost[i];
				}
				else {
					string snext;
					for(int j = 0; j < sz(s) - sz(a[i]); j++) {
						snext += s[j];
					}
					res += cost[i];
					solve(snext, 0);
					res -= cost[i];
				}
			}
		}
	};
	for(int i = 0; i < n; i++) {
		res += cost[i];
		solve(a[i], 1);
		res -= cost[i];
	}
	if(ans == inf) {
		cout << "-1\n";
		return 0;
	}
	cout << ans << "\n";
    return 0;
}

Measured memory_bytes: 3624