#include <bits/stdc++.h>
using namespace std;
long long n, h, ar1[100001];
int main() {
  int n, h;
  cin >> n >> h;
  long long mx = -1;
  for (int i = 0; i < (int)n; ++i) {
    long long a, b;
    cin >> a >> b;
    mx = max(a, mx);
    ar1[i] = b;
  }
  sort(ar1, ar1 + n);
  long long i = n - 1, ans = 0;
  while (i >= 0) {
    if (h < 0 || mx >= ar1[i]) {
      break;
    }
    h -= ar1[i--];
    ans++;
  }
  if (h > 0) {
    ans += ceil((double)h / mx);
  }
  cout << ans;
  return 0;
}
