#include <bits/stdc++.h>
using namespace std;
int main() {
  unsigned long int N, H, sum;
  cin >> N >> H;
  unsigned long int i, meow;
  unsigned long int a[N], b[N];
  for (i = 0; i < N; i++) {
    cin >> a[i] >> b[i];
  }
  sum = 0;
  sort(a, a + N);
  reverse(a, a + N);
  sort(b, b + N);
  reverse(b, b + N);
  unsigned long int m = a[0];
  for (i = 0; i < N; i++) {
    if (b[i] < m) {
      meow = i;
      break;
    }
    sum += b[i];
    if (sum >= H) {
      cout << i + 1 << endl;
      return 0;
    }
  }
  H -= sum;
  unsigned long int n = 1;
  while (1) {
    if (m * n >= H) {
      cout << meow + n << endl;
      return 0;
    }
    n++;
  }
}
