//#pragma comment(linker, "/STACK:1024000000,1024000000")
/* vim: set fdm=marker */
//{{{
#define __ return
int ATTENTION() {
	/* pls IGNORE this function and go down and HACK me
	 * read this AFTER contest
	 * this function is empty and it will not be called !
	 */

	http://codeforces.com/group/Pmz2A2x7ES
	/* I created a group there.
	 * I hope with the group, people can finish
	 * past contests, which is important for 
	 * increasing rating.
	 * I am still getting familiar with this function.
	 */
	 __ 0;
}
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
const int iinf = 0x7fffffff;
const ll linf = ~(1LL<<63);
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef map<ll, int> mli;
typedef map<ll, ll> mll;
template<typename T>
inline T gcd(T a, T b) {
	if(a < 0) return gcd(-a, b);
	if(b < 0) return gcd( a,-b);
	if(a < b) return gcd(b, a);
	if(b == 0) return a;
	return gcd(b, a%b);
}

ll qpow(ll a, ll n, ll mod) {
	a %= mod;
	ll ans = 1LL;
	while(n) {
		if(n & 1) ans = (ans*a % mod);
		a = (a*a % mod);
		n >>= 1;
	}
	return ans;
}

inline ll rev(ll a, ll p) {
	return qpow(a, p - 2, p);
}

#define all(v) v.begin(), v.end()
#define sz(v) v.size()
#define rep(x, st, en) for(int x = st; x < en; x++)
#define rer(x, st, en) for(int x = st; x >= en; x--)
#define pb push_back
#define mp make_pair
#define dbgm(msg, var) cerr<<#msg<<" "<<#var<<" = "<<var<<endl; 
#define dbg(var) cerr<<#var<<" = "<<var<<endl;
#define X first
#define Y second
// build prefix sum
template<typename T>
inline void BPS(T* DST, T* SRC, int N, int s = 0) {
	DST[s] = SRC[s];
	rep(i, 1, N) DST[s + i] = DST[s + i - 1] + SRC[s + i];
}
inline int in() { int x; cin>>x; return x; }
#ifdef ALNDBG
namespace alndbg {
	clock_t s, e;
}
#endif

inline void tic() {
#ifdef ALNDBG
	alndbg::s = clock();
#endif
}

inline void toc() {
#ifdef ALNDBG
	alndbg::e = clock();
	cerr<<1000.0 * (alndbg::e - alndbg::s) / CLOCKS_PER_SEC<<" ms"<<endl;
#endif
}



//}}}

// -------------------- Spliters ------------------------
// BFS求最短路小心vis可能访问过
const int maxn = 100111;
ll h;
int n;
ll a[maxn], b[maxn];

int main() {
	ios::sync_with_stdio(0);
  cin>>n>>h;
  ll amax = -1;
  int ans = 0;
  rep(i,0,n) {
    cin>>a[i]>>b[i];
    amax = max((ll)a[i], amax);
  }
  for(int pkatana = 0; pkatana < n; pkatana++) {
    if(b[pkatana] >= amax) {
      h -= b[pkatana];
      ans++;
      if(h <= 0) break;
    }
  }
  if(h > 0) {
    int c = h / amax;
    if(c * amax < h) c++;
    ans += c;
  }
  cout<<ans<<endl;
	return 0;
}
// --USE C++11
// *-USE O2
