#include <bits/stdc++.h>
using namespace std;
const long long INFL = 1e18;
const int INF = 1001001001;
const int mod = 1000000007;
int main() {
  int n, h;
  cin >> n >> h;
  vector<int> B;
  int ma, pb;
  for (int(i) = 0; (i) < (n); (i)++) {
    int a, b;
    cin >> a >> b;
    if (a > ma) {
      ma = a;
      pb = b;
    }
    B.push_back(b);
  }
  sort((B).begin(), (B).end());
  B.erase(lower_bound((B).begin(), (B).end(), pb));
  sort((B).begin(), (B).end(), greater<int>());
  int ans = 0;
  for (int(i) = 0; (i) < (n - 1); (i)++) {
    if (B[i] < ma) break;
    h -= B[i];
    ans++;
  }
  while (h > pb) {
    h -= ma;
    ans++;
  }
  ans++;
  cout << ans << endl;
}
