#include <bits/stdc++.h>
using namespace std;
struct Sword {
  long long x;
  long long y;
};
bool com1(struct Sword a, struct Sword b) { return a.y >= b.y; }
struct Sword s[100010];
int main() {
  long long n, h;
  cin >> n >> h;
  long long i, maxn = 0, count = 0;
  for (i = 0; i < n; i++) {
    cin >> s[i].x >> s[i].y;
    if (s[i].x >= maxn) {
      maxn = s[i].x;
    }
  }
  for (i = 0; i < n; i++) {
    if (s[i].y >= maxn && h > 0) {
      h -= s[i].y;
      count++;
    }
  }
  long long r = h / maxn;
  if (r > 0) {
    if (maxn * r < h) {
      r++;
    }
    count += r;
  }
  cout << count << endl;
  return 0;
}
