#include <bits/stdc++.h>
inline int read() {
  int f = 1, x = 0;
  char c = getchar();
  while (c < '0' || c > '9') {
    if (c == '-') f = -1;
    c = getchar();
  }
  while (c <= '9' && c >= '0') {
    x = x * 10 + c - '0';
    c = getchar();
  }
  return x * f;
}
inline void file() {
  freopen("1.in", "r", stdin);
  freopen("1.out", "w", stdout);
}
using namespace std;
const long long maxn = 1e6 + 10;
long long a[maxn], b[maxn];
int main() {
  file();
  long long k, n, h;
  cin >> n >> h;
  for (register long long i = 1; i <= n; ++i) cin >> a[i] >> b[i];
  sort(a + 1, a + n + 1);
  for (register long long i = 1; i <= n; ++i) b[i] = max(b[i], a[n]);
  sort(b + 1, b + n + 1);
  long long ovo = 0;
  for (register long long i = n; i >= 1; --i) {
    ovo += b[i];
    if (ovo >= h) {
      printf("%lld", n - i + 1);
      return 0;
    }
  }
  int ans = n;
  ans += (h - ovo) / a[n];
  if ((h - ovo) % a[n]) ++ans;
  cout << ans;
  return 0;
}
