#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define F first
#define S second
#define pii pair<int, int>
#define eb emplace_back
#define all(v) v.begin(), v.end()
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep3(i, l, n) for (int i = l; i < (n); ++i)
#define sz(v) (int)v.size()
const int inf = 1e9 + 7;
const ll INF = 1e18;
// int mod = 998244353;
int mod = 1000000007;
#define abs(x) (x >= 0 ? x : -(x))
#define lb(v, x) (int)(lower_bound(all(v), x) - v.begin())
#define ub(v, x) (int)(upper_bound(all(v), x) - v.begin())
template<typename T1, typename T2> inline bool chmin(T1 &a, T2 b) { if (a > b) { a = b; return 1; } return 0; }
template<typename T1, typename T2> inline bool chmax(T1 &a, T2 b) { if (a < b) { a = b; return 1; } return 0; }
ll gcd(ll a, ll b) { if (b == 0) return a; return gcd(b, a % b); }
ll lcm(ll a, ll b) { return a / gcd(a, b) * b; }
ll pow(ll a, int b) { return b ? pow(a * a, b / 2) * (b % 2 ? a : 1) : 1; }
ll modpow(ll a, ll b, ll _mod) { return b ? modpow(a * a % _mod, b / 2, _mod) * (b % 2 ? a : 1) % _mod : 1; }
template<class T, class U> ostream& operator << (ostream& os, const pair<T, U>& p) { os << p.F << " " << p.S; return os; }
template<class T> ostream& operator << (ostream& os, const vector<T>& vec) { rep(i, sz(vec)) { if (i) os << " "; os << vec[i]; } return os; }
template<typename T> inline istream& operator >> (istream& is, vector<T>& v) { rep(j, sz(v)) is >> v[j]; return is; }
template<class T, class T2> inline void add(T &a, T2 b) { a += b; if (a >= mod) a -= mod; }


void solve();

int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  cout << fixed << setprecision(10);

  int T;
  // cin >> T;
  T = 1;

  while (T--) {
    solve();
  }
}

void solve() {
  int n, k;
  cin >> n >> k;
  vector<string> s(n);
  vector<int> c(n);
  rep(i, n) cin >> s[i] >> c[i];

  vector<vector<vector<int> > > v(n);
  rep(i, n) {
    v[i] = vector<vector<int> >(3, vector<int>(sz(s[i]) + 1));
    rep(j, sz(s[i])) {
      if (s[i][j] == 'J') v[i][0][j + 1] = 1;
      else if (s[i][j] == 'O') v[i][1][j + 1] = 1;
      else v[i][2][j + 1] = 1;
    }
  }
  // cout << endl; rep(i, n) rep(j, 3) cout << v[i][j] << endl;
  rep(i, n) rep(j, 3) rep(l, sz(v[i][j]) - 1) v[i][j][l + 1] += v[i][j][l];
  // cout << endl; rep(i, n) rep(j, 3) cout << v[i][j] << endl;
  vector<ll> dp(3 * k + 1, INF);
  dp[0] = 0;
  rep(i, 3 * k) rep(j, n) {
    vector<int> x(3);
    if (i <= k) x[0] = i;
    else if (i <= 2 * k) { x[0] = k; x[1] = i - k; }
    else { x[0] = k; x[1] = k; x[2] = i - 2 * k; }
    int nxt, m = sz(s[j]) + 1;
    int it = lb(v[j][0], k - x[0]);
    // cout << endl << it << endl;
    if (it == m) {
      nxt = x[0] + v[j][0][m - 1];
    } else {
      int it2 = lb(v[j][1], k - x[1] + v[j][1][it]);
      // cout << it2 << endl;
      if (it2 == m) {
        nxt = k + x[1] + (v[j][1][m - 1] - v[j][1][it]);
      } else {
        int it3 = lb(v[j][2], k - x[2] + v[j][2][it2]);
        // cout << it3 << endl;
        if (it3 == m) {
          nxt = 2 * k + x[2] + (v[j][2][m - 1] - v[j][2][it2]);
        } else {
          nxt = 3 * k;
        }
      }
    }
    // cout << i << " " << j << " " << nxt << endl;
    chmin(dp[nxt], dp[i] + c[j]);
  }
  cout << (dp[3 * k] == INF ? -1 : dp[3 * k]) << endl;
  // cout << dp << endl;
}