#include <bits/stdc++.h>  // ver2.1.4
#define int long long
#define endl "\n"
#define ALL(v) (v).begin(),(v).end()
#define Vi vector<int>
#define Pii pair<int,int>
#define Tiii tuple<int,int,int>
#define PQi priority_queue<int>
#define PQir priority_queue<int, vector<int>, greater<int>>
#define pb push_back
#define mp make_pair
#define mt make_tuple
#define cYES cout<<"YES"<<endl
#define cNO cout<<"NO"<<endl
#define cYes cout<<"Yes"<<endl
#define cNo cout<<"No"<<endl
#define sortr(v) sort(v,greater<>())
#define rep(i,a,b) for(int i=a;i<b;i++)
#define repeq(i,a,b) for(int i=a;i<=b;i++)
#define repr(i,a,b) for(int i=a;i>b;i--)
#define repreq(i,a,b) for(int i=a;i>=b;i--)
#define leng(n) (int)(log10(n)+1)
#define dem(a,b) ((a+b-1)/(b))
#define Vout(a) rep(i,0,a.size()-1)cout<<a[i]<<' ';cout<<a.back()<<endl
#define INF 9000000000000000000  //  9.0 * 10^18
#define MOD 1000000007  //  10^9 + 7
using namespace std;

int mypow(int x, int n, int m){  //  高速累乗x^n(mod m)  O(log(n))
if(n==0)return 1;if(n%2==0)return mypow(x*x%m,n/2,m);else return x*mypow(x,n-1,m)%m;}

signed main() {
  cin.tie(0);cout.tie(0);ios::sync_with_stdio(false);cout<<fixed<<setprecision(12);
  int n,h;
  cin >> n >> h;
  Vi a(n),b(n);
  rep(i,0,n) cin >> a[i] >> b[i];
  int maxa = *max_element(ALL(a));
  sortr(ALL(b));
  int sumb=0,ans =0;
  rep(i,0,n){
    sumb += b[i];
    ans++;
    if(sumb >= h){cout<<ans<<endl;return 0;}
  }
  int nkr = h-sumb;
  ans += dem(nkr,maxa);
  cout << ans << endl;
  return 0;
}