#include <bits/stdc++.h>
using namespace std;
int b[100010], ans;
int main() {
  int n, h, k, a = -1000000010;
  scanf("%d%d", &n, &h);
  for (int i = 1; i <= n; ++i) {
    scanf("%d%d", &k, &b[i]);
    a = max(a, k);
  }
  sort(b + 1, b + 1 + n);
  for (int i = n; i >= 1; --i) {
    if (a >= b[i]) {
      int tmp = h / a;
      int yu = h % a;
      if (yu > 0) ans++;
      ans += tmp;
      h = 0;
      break;
    } else {
      h -= b[i];
      ans++;
    }
  }
  if (h > 0) {
    int tmp = h / a;
    ans += tmp + 1;
  }
  printf("%d\n", ans);
  return 0;
}
