#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b;
  cin >> a >> b;
  int ans = 0;
  int c = 0, d[a];
  for (int i = 0; i < a; i++) {
    int e;
    cin >> e >> d[i];
    c = max(c, e);
  }
  sort(d, d + a);
  for (int i = a - 1; i >= 0; i--) {
    if (d[i] < c) break;
    if (b < 0) break;
    b -= d[i];
    ans++;
  }
  if (b > 0) {
    ans += b / c;
    if (b % c) ans++;
  }
  cout << ans << endl;
}
