#include <bits/stdc++.h>

using i32 = int_fast32_t;
using i64 = int_fast64_t;
using u32 = uint_fast32_t;
using u64 = uint_fast64_t;
using f64 = double;
using f80 = long double;

#define FOR(v, a, b) for(i64 v = (a); v < (b); ++v)
#define FORE(v, a, b) for(i64 v = (a); v <= (b); ++v)
#define REP(v, n) FOR(v, 0, n)
#define REPE(v, n) FORE(v, 0, n)
#define REV(v, a, b) for(i64 v = (a); v >= (b); --v)
#define ALL(x) (x).begin(), (x).end()
#define RALL(x) (x).rbegin(), (x).rend()
#define ITR(it, c) for(auto it = (c).begin(); it != (c).end(); ++it)
#define RITR(it, c) for(auto it = (c).rbegin(); it != (c).rend(); ++it)
#define EXIST(c,x) ((c).find(x) != (c).end())
#define fst first
#define snd second
#define UNIQ(v) (v).erase(unique(ALL(v)), (v).end())
#define bit(i) (1LL<<(i))

#ifdef DEBUG
#include <Mylib/Debug/debug.cpp>
#else
#define dump(...) ((void)0)
#endif

using namespace std;

template <typename I> void join(ostream &ost, I s, I t, string d=" "){for(auto i=s; i!=t; ++i){if(i!=s)ost<<d; ost<<*i;}ost<<endl;}
template <typename T> istream& operator>>(istream &is, vector<T> &v){for(auto &a : v) is >> a; return is;}
template <typename T> void pout(const T &value){std::cout << value << "\n";}
template <typename T, typename ...Args> void pout(const T &value, const Args&... args){std::cout << value << " ";pout(args...);}

template <typename T, typename U> bool chmin(T &a, const U &b){return (a>b ? a=b, true : false);}
template <typename T, typename U> bool chmax(T &a, const U &b){return (a<b ? a=b, true : false);}
template <typename T, size_t N, typename U> void fill_array(T (&a)[N], const U &v){fill((U*)a, (U*)(a+N), v);}
template <typename T> auto make_vector(int n, int m, const T &value){return vector<vector<T>>(n, vector<T>(m, value));}


struct Init{
  Init(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    cout << fixed << setprecision(12);
    cerr << fixed << setprecision(12);
  }
}init;


const i64 INF = 1LL << 60;


int main(){
  int N, K; cin >> N >> K;
  N += 1;
  vector<string> S(N);
  vector<i64> C(N);

  vector<int> cj(N), co(N), ci(N);

  REP(i,N-1) cin >> S[i] >> C[i];
  S.push_back("");
  C.push_back(0);

  {
    bool J = false, O = false, I = false;
    
    REP(i,N){
      cj[i] = count(ALL(S[i]), 'J');
      co[i] = count(ALL(S[i]), 'O');
      ci[i] = count(ALL(S[i]), 'I');
    
      if(cj[i]) J = true;
      if(co[i]) O = true;
      if(ci[i]) I = true;
    }

    if(not (J and O and I)){
      pout(-1);
      return 0;
    }
  }

  i64 ans = INF;

  auto dp_j = vector<i64>(K+100, INF);
  auto dp_o = vector<i64>(K+100, INF);
  auto dp_i = vector<i64>(K+100, INF);

  dp_j[0] = 0;
  dp_o[0] = 0;
  dp_i[0] = 0;

  FORE(j,0,K){
    REP(i,N){
      chmin(dp_j[j+cj[i]], dp_j[j] + C[i]);
      chmin(dp_o[j+co[i]], dp_o[j] + C[i]);
      chmin(dp_i[j+ci[i]], dp_i[j] + C[i]);
    }
  }

  REV(j,K+80,0) chmin(dp_j[j], dp_j[j+1]);
  REV(j,K+80,0) chmin(dp_o[j], dp_o[j+1]);
  REV(j,K+80,0) chmin(dp_i[j], dp_i[j+1]);
  


  vector<vector<int>> jo(N), oi(N);

  REP(i,N){
    int O = co[i];
    int I = ci[i];

    jo[i].push_back(O);
    oi[i].push_back(I);
    
    for(auto c : S[i]){
      if(c == 'I') I -= 1;
      if(c == 'O') O -= 1, oi[i].push_back(I);
      if(c == 'J') jo[i].push_back(O);
    }
  }

  REP(i,N){
    REP(j,N){
      REPE(x,cj[i]){
        REPE(y,co[j]){
          chmin(ans, dp_j[max<int>(0, K-x)] + C[i] + dp_o[max<int>(0, K-y-jo[i][x])] + C[j] + dp_i[max<int>(0, K-oi[j][y])]);
        }
      }
    }
  }


  

  REP(i,N){
    REP(x,S[i].size()){
      FOR(y,x,S[i].size()){
        int J = count(S[i].begin(), S[i].begin() + x, 'J');
        int O = count(S[i].begin() + x, S[i].begin() + y, 'O');
        int I = count(S[i].begin() + y, S[i].end(), 'I');

        if(O >= K){
          chmin(ans, dp_j[max<int>(0, K-J)] + C[i] + dp_i[max<int>(0,K-I)]);
        }
      }
    }
  }
  
  
  pout(ans);

  return 0;
}