#include <bits/stdc++.h>
using namespace std;
const int INF = 1e9;
int main() {
  int n, h;
  cin >> n >> h;
  vector<int> b(n);
  int mx = 0;
  for (int i = 0; i < (n); i++) {
    int a;
    cin >> a >> b[i];
    mx = max(mx, a);
  }
  sort(b.begin(), b.end(), greater<int>());
  long long sum = 0;
  long long ret = INF;
  for (int i = n; i >= 0; i--) {
    if (i != n) sum += b[i];
    ret = min(ret, (n - i) + (max(0LL, h - sum) + mx - 1) / mx);
  }
  cout << ret << endl;
  return 0;
}
