#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n, h, c = 0, d = 0, e = 0;
  cin >> n >> h;
  int a[n + 1], b[n + 1];
  for (int i = 1; i <= n; i++) {
    cin >> a[i] >> b[i];
    c += b[i];
    d = max(d, a[i]);
  }
  for (int i = 1; i <= n; i++) {
    if (b[i] > d) e += b[i];
  }
  if (c >= h)
    cout << n;
  else {
    h -= e;
    if (h % d)
      cout << 1 + h / d;
    else
      cout << h / d;
  }
}
