#include <iostream>
#include <vector>
#include <cstring>
using namespace std;

int N, M;
vector< vector <int> > kovanice;
vector <int> B, C, S, Z, P;

int memo[1024][5];

int rek(int sada, int zadnja) {
  if (sada < 0) {
    return 1000;
  }
  if (sada == 0) {
    return 0;
  }

  if (memo[sada][zadnja] != -1) {
    return memo[sada][zadnja];
  }

  int min = 1000;

  for (int boja = 0; boja < 5; boja++) {
    if (boja == zadnja) {
      continue;
    }
    for (int i = 0; i < kovanice[boja].size(); i++) {
      int mini = rek(sada - kovanice[boja][i], boja) + 1;
      if (mini < min) {
        min = mini;
      }
    }
  }

  memo[sada][zadnja] = min;
  return min;
}

int main() {
  cin >> N >> M;

  for (int i = 0; i < N; i++) {
    int x; char b;
    scanf("%d %c", &x, &b);

    if (b == 'B') {
      B.push_back(x);
    } else if (b == 'C') {
      C.push_back(x);
    } else if (b == 'S') {
      S.push_back(x);
    } else if (b == 'Z') {
      Z.push_back(x);
    } else if (b == 'P') {
      P.push_back(x);
    }
  }

  kovanice.push_back(B);
  kovanice.push_back(C);
  kovanice.push_back(S);
  kovanice.push_back(Z);
  kovanice.push_back(P);

  memset(memo, -1, sizeof(memo));
  cout << rek(M, 5) << endl;

  return 0;
}