#include <bits/stdc++.h>
using namespace std;
using LL = long long int;
#define incID(i, l, r) for(int i = (l)    ; i <  (r); ++i)
#define decID(i, l, r) for(int i = (r) - 1; i >= (l); --i)
#define incII(i, l, r) for(int i = (l)    ; i <= (r); ++i)
#define decII(i, l, r) for(int i = (r)    ; i >= (l); --i)
#define inc(i, n)  incID(i, 0, n)
#define dec(i, n)  decID(i, 0, n)
#define inc1(i, n) incII(i, 1, n)
#define dec1(i, n) decII(i, 1, n)
#define inID(v, l, r) ((l) <= (v) && (v) <  (r))
#define inII(v, l, r) ((l) <= (v) && (v) <= (r))
#define PB push_back
#define EB emplace_back
#define MP make_pair
#define FI first
#define SE second
#define FR front()
#define BA back()
#define ALL(v) v.begin(), v.end()
#define RALL(v) v.rbegin(), v.rend()
auto setmin   = [](auto & a, auto b) { return (b <  a ? a = b, true : false); };
auto setmax   = [](auto & a, auto b) { return (b >  a ? a = b, true : false); };
auto setmineq = [](auto & a, auto b) { return (b <= a ? a = b, true : false); };
auto setmaxeq = [](auto & a, auto b) { return (b >= a ? a = b, true : false); };
#define SI(v) static_cast<int>(v.size())
#define RF(e, v) for(auto & e: v)
#define until(e) while(! (e))
#define if_not(e) if(! (e))
#define ef else if
#define UR assert(false)
#define IN(T, ...) T __VA_ARGS__; IN_(__VA_ARGS__);
void IN_() { };
template<typename T, typename ... U> void IN_(T & a, U & ... b) { cin >> a; IN_(b ...); };
template<typename T> void OUT(T && a) { cout << a << endl; }
template<typename T, typename ... U> void OUT(T && a, U && ... b) { cout << a << " "; OUT(b ...); }

// ---- ----

template<typename T> istream & operator>>(istream & s, vector<T> & v) { RF(e, v) { s >> e; } return s; }
template<typename T> ostream & operator<<(ostream & s, vector<T> const & v) {
	inc(i, SI(v)) { s << (i == 0 ? "" : " ") << v[i]; }
	return s;
}

template<typename T, typename U> istream & operator>>(istream & s, pair<T, U> & p) { return (s >> p.FI >> p.SE); }
template<typename T, typename U> ostream & operator<<(ostream & s, pair<T, U> const & p) { return (s << p.FI << " " << p.SE); }

template<typename T> T MV(T v) { return v; }
template<typename T, typename ... U> auto MV(T v, int a, U ... b) { return vector<decltype(MV(v, b ...))>(a, MV(v, b ...)); }

int main() {
	IN(int, n, k);
	vector<pair<string, LL>> v(n);
	cin >> v;
	
	const int m = min(80, k);
	auto w = MV(0, n, m + 2, m + 2);
	inc(i, n) {
		inc(J, m + 2) {
		inc(O, m + 2) {
			int j = 0, o = 0;
			auto & r = w[i][J][O];
			RF(e, v[i].FI) {
				if(e == 'J' && j <  J          ) { r++; j++; }
				if(e == 'O' && j == J && o <  O) { r++; o++; }
				if(e == 'I' && j == J && o == O) { r++; }
			}
		}
		}
	}
	
	const LL INF = 1e15;
	vector<LL> dp(3 * k + 1, INF);
	dp[0] = 0;
	inc(p, 3 * k) {
	inc(i, n) {
		int j = clamp(1 * k - p, 0, min(k, m + 1));
		int o = clamp(2 * k - p, 0, min(k, m + 1));
		setmin(dp[min(p + w[i][j][o], 3 * k)], dp[p] + v[i].SE);
	}
	}
	OUT(dp.BA == INF ? -1 : dp.BA);
}