#include <bits/stdc++.h>
using namespace std;
using namespace std;
long long arr[100000];
long long brr[100000];
int main() {
  long long n, h;
  cin >> n >> h;
  long long sum = 0, ma = 0, p = 0;
  long long num = 0, flag = 0;
  for (long long i = 0; i < n; i++) {
    cin >> arr[i] >> brr[i];
    if (ma < brr[i]) {
      ma = brr[i];
      p = i;
    }
  }
  for (int i = 0; i < n; i++) {
    if (brr[i] > ma && p != i) {
      sum += brr[i];
      num++;
    }
    if (sum >= h) {
      flag = 1;
      break;
    }
  }
  if (flag)
    cout << num << endl;
  else {
    double kk = (double)(h - sum) / ma;
    num += ceil(kk);
    cout << num << endl;
  }
  return 0;
}
