#include <bits/stdc++.h>
const int MOD = 1000000007;
using namespace std;
int main() {
  int n, m;
  long long h;
  cin >> n >> h;
  vector<long long> a(n), b(n);
  long long amax = 0;
  long long count = 0;
  for (int(i) = 0; (i) < (n); (i)++) {
    cin >> a[i] >> b[i];
    if (amax < a[i]) {
      amax = a[i];
      m = i;
    }
  }
  for (int(i) = 0; (i) < (n); (i)++) {
    if (i == m) {
      continue;
    }
    if (b[i] > amax) {
      h -= b[i];
      count++;
    }
  }
  count += (h / amax) - 1;
  h -= amax * ((h / amax) - 1);
  if (h <= b[m]) {
    count++;
  } else {
    count += 2;
  }
  cout << count << endl;
  return 0;
}
