#include <bits/stdc++.h>
using namespace std;
int a[100001];
int b[100001];
int main(int argc, const char* argv[]) {
  int n, h;
  scanf("%d %d", &n, &h);
  int ma = 0;
  int ai = 0;
  for (int i = 0; i < n; i++) {
    scanf("%d %d", &a[i], &b[i]);
    if (ma < a[i]) {
      ma = a[i];
      ai = i;
    }
  }
  sort(b, b + n);
  int ans = 0;
  for (int i = n - 1; i >= 0; i--) {
    if (ma > b[i]) {
      break;
    } else {
      h = h - b[i];
      ans++;
      if (h <= 0) break;
    }
  }
  if (h % ma != 0 && h > 0) {
    ans += 1;
  }
  printf("%d\n", ans + h / ma);
  return 0;
}
