#include<bits/stdc++.h>
#define ALL(v) std::begin(v),std::end(v)
using lint=long long;
using ld=long double;
template<class T>using numr=std::numeric_limits<T>;
void cmn(lint&x,lint y){if(x>y)x=y;}
int main(){
    std::cin.tie(nullptr);std::ios_base::sync_with_stdio(false);
    std::cout.setf(std::ios_base::fixed);std::cout.precision(15);
    lint n,V;std::cin>>n>>V;
    std::vector<std::vector<std::vector<lint>>>a(n,std::vector<std::vector<lint>>(3));
    std::vector<lint>sz(n),ws(n);
    for(lint i=0;i<n;i++){
        std::string s;std::cin>>s>>ws.at(i);
        sz.at(i)=s.length();
        for(lint j=0;j<3;j++){
            a.at(i).at(j).resize(sz.at(i)+1);
            for(lint k=0;k<sz.at(i);k++){
                a.at(i).at(j).at(k+1)=s.at(k)==std::string("JOI").at(j);
            }
            std::partial_sum(ALL(a.at(i).at(j)),a.at(i).at(j).begin());
        }
    }
    auto count=[&](lint i,lint j,lint l,lint r)->lint{
        return a.at(i).at(j).at(r)-a.at(i).at(j).at(l);
    };
    for(lint j=0;j<3;j++){
        lint sum=0;
        for(lint i=0;i<n;i++){
            sum+=count(i,j,0,sz.at(i));
        }
        if(sum==0){
            std::cout<<-1<<'\n';
            return 0;
        }
    }
    lint inf=numr<lint>::max();
    std::vector<std::vector<lint>>dp(3,std::vector<lint>(V+1,inf));
    for(lint j=0;j<3;j++){
        auto&&d=dp.at(j);
        d.at(0)=0;
        for(lint i=0;i<n;i++){
            lint v=count(i,j,0,sz.at(i)),w=ws.at(i);
            if(v==0)continue;
            for(lint k=0;k<V;k++){
                if(d.at(k)==inf)continue;
                cmn(d.at(std::min(V,k+v)),d.at(k)+w);
            }
            for(lint k=V-1;k>=0;k--){
                cmn(d.at(k),d.at(k+1));
            }
        }
    }
    lint ans=inf;
    for(lint i=0;i<n;i++)for(lint j=0;j<n;j++){
        for(lint k=0;k<sz.at(i);k++)for(lint l=0;l<sz.at(j);l++){
            cmn(ans,
                ws.at(i) + ws.at(j)
                + dp.at(0).at(std::max(0ll,V-count(i,0,0,k)))
                + dp.at(1).at(std::max(0ll,V-count(i,1,k,sz.at(i))-count(j,1,0,l)))
                + dp.at(2).at(std::max(0ll,V-count(j,2,l,sz.at(j)))));
        }
    }
    for(lint i=0;i<n;i++){
        for(lint k=0;k<sz.at(i);k++)for(lint l=k+1;l<sz.at(i);l++){
            if(count(i,1,k,l)<V)continue;
            cmn(ans,
                ws.at(i)
                + dp.at(0).at(std::max(0ll,V-count(i,0,0,k)))
                + dp.at(2).at(std::max(0ll,V-count(i,2,l,sz.at(i)))));
        }
    }
    std::cout<<ans<<'\n';
}