#include <bits/stdc++.h>
using namespace std;
int main() {
  long long N, M;
  cin >> N >> M;
  vector<long long> A(N), B(N);
  for (long long i = 0; i < N; i++) {
    cin >> A.at(i) >> B.at(i);
  }
  sort(A.begin(), A.end(), greater<long long>());
  sort(B.begin(), B.end(), greater<long long>());
  for (long long i = 0; i < N; i++) {
    if (B.at(i) >= M) {
      cout << i + 1 << endl;
      return 0;
    }
    M -= B.at(i);
  }
  long long ans = M / A.at(0);
  if (M % A.at(0) != 0) ans++;
  cout << N + ans << endl;
}
