#include<bits/stdc++.h>
using namespace std;
#define ll long long
int main(){
  ll n,k,m=0,c=0,a;
  cin>>n>>k;
  vector<ll> b(n);
  for(int i=0;i<n;i++){
    cin>>a>>b[i];
    m=max(a,m);
  }
  sort(b.begin(),b.end(),greater<ll>());
  for(int i=0;i<n;i++){
    k-=b;
    c++;
    if(k<=0){
      cout<<c;
      return 0;
    }
  }
  cout<<c+(k%m==0?k/m:k/m+1);
}