#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <queue>
#include <string>
#include <map>
#include <set>
#include <stack>
#include <tuple>
#include <deque>
#include <array>
#include <numeric>
#include <bitset>
#include <iomanip>
#include <cassert>
#include <chrono>
#include <random>
#include <limits>
#include <iterator>
#include <functional>
#include <sstream>
#include <fstream>
#include <complex>
#include <cstring>
#include <unordered_map>
#include <unordered_set>
using namespace std;

using ll = long long;
constexpr int INF = 1001001001;
constexpr int mod = 1000000007;
// constexpr int mod = 998244353;

template<class T>
inline bool chmax(T& x, T y){
    if(x < y){
        x = y;
        return true;
    }
    return false;
}
template<class T>
inline bool chmin(T& x, T y){
    if(x > y){
        x = y;
        return true;
    }
    return false;
}

ll dp[300005];
int sum[100][3][100];

int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int N, K;
    cin >> N >> K;
    vector<string> S(N);
    vector<int> C(N), L(N);
    for(int i = 0; i < N; ++i){
        cin >> S[i] >> C[i];
        L[i] = S[i].length();
        for(int j = 0; j < L[i]; ++j){
            if(S[i][j] == 'J')  sum[i][0][j + 1] = 1;
            else if(S[i][j] == 'O') sum[i][1][j + 1] = 1;
            else    sum[i][2][j + 1] = 1;
        }
        for(int j = 0; j < 3; ++j){
            for(int k = 0; k < L[i]; ++k){
                sum[i][j][k + 1] += sum[i][j][k];
            }
        }
    }

    constexpr ll inf = 1e+17;
    for(int i = 0; i <= K * 3; ++i) dp[i] = inf;
    dp[0] = 0;

    for(int i = 0; i < K; ++i){
        if(dp[i] == inf)    continue;
        for(int j = 0; j < N; ++j){
            if(i + sum[j][0][L[j]] < K){
                chmin(dp[i + sum[j][0][L[j]]], dp[i] + C[j]);
            }
            else{
                int rest = K - i;
                for(int k = 0; k < L[j]; ++k){
                    if(S[j][k] == 'J' && --rest == 0){
                        chmin(dp[K + sum[j][1][L[j]] - sum[j][1][k]], dp[i] + C[j]);
                        break;
                    }
                }
            }
        }
    }
    for(int i = K; i < K * 2; ++i){
        if(dp[i] == inf)    continue;
        for(int j = 0; j < N; ++j){
            if(i + sum[j][1][L[j]] < K * 2){
                chmin(dp[i + sum[j][1][L[j]]], dp[i] + C[j]);
            }
            else{
                int rest = K * 2 - i;
                for(int k = 0; k < L[j]; ++k){
                    if(S[j][k] == 'O' && --rest == 0){
                        chmin(dp[K * 2 + sum[j][2][L[j]] - sum[j][2][k]], dp[i] + C[j]);
                        break;
                    }
                }
            }
        }
    }
    for(int i = K * 2; i < K * 3; ++i){
        if(dp[i] == inf)    continue;
        for(int j = 0; j < N; ++j){
            chmin(dp[min(K * 3, i + sum[j][2][L[j]])], dp[i] + C[j]);
        }
    }

    ll ans = dp[K * 3];
    if(ans == inf)  ans = -1;
    cout << ans << endl;

    return 0;
}