#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int main() {
  int n, h;
  cin >> n >> h;
  int a[n], b[n];
  int amax = -1;
  for (int i = 0; i < n; i++) {
    cin >> a[i] >> b[i];
    amax = max(a[i], amax);
  }
  int ans = 990000000;
  sort(b, b + n);
  reverse(b, b + n);
  for (int i = 0; i <= n; i++) {
    int cnt = 0;
    if (i > 0) h -= b[i - 1];
    if (h > 0) cnt = (h + amax - 1) / amax;
    ans = min(cnt + i, ans);
  }
  cout << ans << endl;
  return 0;
}
