#include <bits/stdc++.h>
using namespace std;
int cmp(const void *a, const void *b) { return *(int *)b - *(int *)a; }
int main() {
  long long n, p, sums, j;
  long long w[100000];
  long long t[100000];
  long i;
  cin >> n >> p;
  for (i = 0; i < n; i++) {
    cin >> w[i] >> t[i];
  }
  qsort(w, n + 1, sizeof(long long), cmp);
  qsort(t, n + 1, sizeof(long long), cmp);
  sums = 0;
  j = 0;
  for (i = 0; i < n; i++) {
    if (t[i] >= w[0]) {
      p -= t[i];
      j++;
    }
    if (p <= 0) {
      cout << j;
      return 0;
    }
  }
  j += (ceil((float)p / w[0]));
  cout << j;
  return 0;
}
