#include <bits/stdc++.h>
using namespace std;
void fast() {
  ios_base ::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
}
inline int D() {
  int m;
  cin >> m;
  return m;
}
inline long long lD() {
  long long m;
  cin >> m;
  return m;
}
inline double dD() {
  double m;
  cin >> m;
  return m;
}
int a[100005], b[100005];
int main() {
  int n = D(), k = D();
  for (int i = 0; i < n; ++i) {
    a[i] = D();
    b[i] = D();
  }
  sort(a, a + n);
  int mx = a[n - 1];
  long long sum = 0;
  int c = 0;
  for (int i = 0; i < n; ++i) {
    if (mx <= b[i]) {
      sum += b[i];
      c++;
    }
  }
  if (sum >= k)
    cout << c << "\n";
  else if (mx == 1) {
    cout << c + (k - sum) << "\n";
  } else {
    int idx = (k - sum) / mx;
    if (idx > 0) {
      if (idx * mx + sum < k) idx++;
    }
    cout << idx + c << "\n";
  }
}
