#include <bits/stdc++.h>
using namespace std;
long long a[100005], b[100005];
bool cmp(int x, int y) { return x > y; }
int main() {
  long long n, h;
  while (cin >> n >> h) {
    for (int i = 0; i < n; i++) {
      cin >> a[i] >> b[i];
    }
    sort(a, a + n, cmp);
    long long maxn = a[0], s = 0;
    sort(b, b + n, cmp);
    for (int i = 0; i < n; i++) {
      if (b[i] >= maxn && h >= maxn) {
        h -= b[i];
        s++;
      }
    }
    if (h >= 0) s += h / maxn;
    if (h % maxn != 0) s++;
    cout << s << endl;
  }
  return 0;
}
