#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 1;
const long long M = 1e18;
pair<int, int> p[N];
int main() {
  ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
  int n, h, s = 0, md = 0, x, y;
  cin >> n >> h;
  for (int i = 0; i < (n); i++) {
    cin >> x >> y;
    p[i].second = x, p[i].first = y;
    md = max(md, x);
  }
  sort(p, p + n);
  for (int i = 0; i < (n); i++)
    if (p[i].first > md && h > 0) h -= p[i].first, s++;
  if (h <= 0)
    cout << s << endl;
  else {
    if (h % md) s++;
    cout << s + h / md << endl;
  }
}
