#include <bits/stdc++.h>
using namespace std;
int n, h, a, b, b_max, c = 0;
int x[100005], y[100005];
bool j = false;
int main() {
  cin >> n >> h;
  for (int i = 0; i < n; i++) {
    cin >> x[i] >> y[i];
  }
  sort(x, x + n, greater<int>());
  sort(y, y + n, greater<int>());
  y[n] = 0;
  for (int i = 0; y[i] > x[0]; i++) {
    h -= y[i];
    c++;
    if (h <= 0) {
      j = true;
      break;
    }
  }
  if (j == false) {
    c += (h / x[0]);
  }
  cout << c << endl;
  return 0;
}
