#include <bits/stdc++.h>
using namespace std;
int main() {
  int N, H, B[10010];
  int amax = 0;
  int cnt = 0;
  cin >> N >> H;
  for (int i = 0; i < N; i++) {
    int a;
    cin >> a >> B[i];
    amax = max(a, amax);
  }
  sort(B, B + N);
  for (int i = N - 1; i >= 0; i--) {
    if (B[i] >= amax) {
      H -= B[i];
      cnt++;
    }
    if (H <= 0) {
      cout << cnt << endl;
      return 0;
    }
  }
  cout << cnt + (H + amax - 1) / amax << endl;
  return 0;
}
