#include <bits/stdc++.h>
using namespace std;
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  long long int n, h, a[100010], b[100010], ma = 0;
  cin >> n >> h;
  for (int i = 0; i < n; i++) {
    cin >> a[i] >> b[i];
    ma = max(ma, a[i]);
  }
  long long int cnt = 0, yan[100010];
  for (int i = 0; i < n; i++) {
    if (b[i] > ma) {
      yan[cnt] = b[i];
      cnt++;
    }
  }
  sort(yan, yan + cnt);
  for (int i = cnt - 2; i >= 0; i--) yan[i] += yan[i + 1];
  long long int yojo, ans = 1e9, num;
  for (int i = 0; i < cnt; i++) {
    yojo = h;
    yojo -= yan[i];
    num = cnt - i;
    if (yojo > 0) {
      num += (yojo + ma - 1) / ma;
    }
    ans = min(ans, num);
  }
  cout << ans << endl;
  return 0;
}
