#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e5 + 10;
int n, m, a[maxn], b[maxn], cnt;
int main() {
  scanf("%d%d", &n, &m);
  for (register int i = 1; i <= n; ++i) scanf("%d%d", &a[i], &b[i]);
  sort(a + 1, a + n + 1);
  sort(b + 1, b + n + 1);
  int i = n;
  while (b[i] >= a[n]) {
    m -= b[i];
    i--;
    cnt++;
  }
  cnt += ceil(m * 1.0 / a[n]);
  cout << cnt << endl;
  return 0;
}
