#include <bits/stdc++.h>
using namespace std;
template <class A>
void pr(A a) {
  cout << a;
  cout << '\n';
}
template <class A, class B>
void pr(A a, B b) {
  cout << a << ' ';
  pr(b);
}
template <class A, class B, class C>
void pr(A a, B b, C c) {
  cout << a << ' ';
  pr(b, c);
}
template <class A, class B, class C, class D>
void pr(A a, B b, C c, D d) {
  cout << a << ' ';
  pr(b, c, d);
}
template <class A>
void PR(A a, long long n) {
  for (long long i = (long long)(0); i < (long long)(n); i++) {
    if (i) cout << ' ';
    cout << a[i];
  }
  cout << '\n';
}
long long check(long long n, long long m, long long x, long long y) {
  return x >= 0 && x < n && y >= 0 && y < m;
}
const long long MAX = 1000000007, MAXL = 1LL << 61, dx[4] = {-1, 0, 1, 0},
                dy[4] = {0, 1, 0, -1};
long long n, h, M = 0;
pair<long long, long long> a[111111];
long long calc(long long m) {
  long long c = m;
  long long x = h;
  x -= m * M;
  for (long long i = (long long)(0); i < (long long)(n); i++) {
    if (x <= 0) break;
    x -= a[i].first;
    c++;
  }
  if (x > 0) return MAXL;
  return c;
}
void Main() {
  cin >> n >> h;
  for (long long i = (long long)(0); i < (long long)(n); i++) {
    cin >> a[i].second >> a[i].first;
    M = max(M, a[i].second);
  }
  sort(a, a + n, greater<pair<long long, long long> >());
  long long l = -1, r = MAX;
  for (long long t = (long long)(0); t < (long long)(400); t++) {
    long long m1 = (l * 2 + r) / 3, m2 = (l + r * 2) / 3;
    long long d1 = calc(m1), d2 = calc(m2);
    if (d1 > d2)
      l = m1;
    else
      r = m2;
  }
  long long ans = MAXL;
  for (long long i = (long long)(l - 5); i < (long long)(r + 5); i++) {
    long long x = calc(i);
    if (i >= 0) ans = min(ans, x);
  }
  pr(ans);
}
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  Main();
  return 0;
}
