#include <bits/stdc++.h>
using namespace std;
bool cmp(long long a, long long b) { return a > b; }
int main() {
  long long n, h;
  cin >> n >> h;
  long long thrown[n + 5];
  long long mx = INT_MIN;
  for (int i = 0; i < n; i++) {
    long long tmp;
    cin >> tmp >> thrown[i];
    mx = max(tmp, mx);
  }
  sort(thrown, thrown + n, cmp);
  long long cnt = 0, sum = 0;
  for (int i = 0; i < n; i++) {
    if (thrown[i] < mx) break;
    sum += thrown[i];
    cnt++;
    if (sum >= h) break;
  }
  if (sum < h) {
    cnt = cnt + ((h - sum) / mx);
    if ((h - sum) % mx != 0) cnt++;
  }
  cout << cnt << endl;
  return 0;
}
