#include "bits/stdc++.h"
using namespace std;
#define int long long
#define FOR(i, a, b) for(int i=(a);i<(b);i++)
#define RFOR(i, a, b) for(int i=(b-1);i>=(a);i--)
#define REP(i, n) for(int i=0; i<(n); i++)
#define RREP(i, n) for(int i=(n-1); i>=0; i--)
#define REP1(i, n) for(int i=1; i<=(n); i++)
#define RREP1(i, n) for(int i=(n); i>=1; i--)
#define ALL(a) (a).begin(),(a).end()
#define UNIQUE_SORT(l) sort(ALL(l)); l.erase(unique(ALL(l)), l.end());
#define CONTAIN(a, b) find(ALL(a), (b)) != (a).end()
#define out(...) printf(__VA_ARGS__)

int dxy[] = {0, 1, 0, -1, 0};

void solve();
signed main()
{
#if DEBUG
    std::ifstream in("input.txt");
    std::cin.rdbuf(in.rdbuf());
#endif
    cin.tie(0);
    ios::sync_with_stdio(false);
    solve();
    return 0;
}

/*================================*/
#if DEBUG
#define SIZE 100
#define SIZE2 20
#else
#define SIZE 100
#define SIZE2 543210
#endif

int N,K;
string S[SIZE];
int C[SIZE], J[SIZE], OS[SIZE], I[SIZE];
int DP[SIZE2];

void solve() {
    cin>>N>>K;
    REP(i,N)cin>>S[i]>>C[i];
    REP(i,N) {
        for (char c:S[i]) {
            if (c=='J') J[i]++;
            if (c=='O') OS[i]++;
            if (c=='I') I[i]++;
        }
    }
    int init = LONG_LONG_MAX/3;
    REP(i,4*K) DP[i]=init;
    DP[0]=0;
    // J/O/Iを使った個数→最低金額
    REP(i,K*3)REP(j,N) {
        int n = i;
        if (n + J[j] < K) n = n + J[j];
        else if (K <= n && n + OS[j] < 2*K) n = n + OS[j];
        else if (2*K <= n && n + I[j] < 3*K) n = n + I[j];
        else {
            REP(k,S[j].size()) {
                if (n >= 3*K) break;
                if (n < K && S[j][k]=='J') n++;
                if (n >= K && n < 2*K && S[j][k]=='O') n++;
                if (n >= 2*K && n < 3*K && S[j][k]=='I') n++;
            }
        }
        DP[n] = min(DP[n], DP[i]+C[j]);
    }
    int ans = (DP[3*K]==init) ? -1 : DP[3*K];
    cout << ans << endl;
}