#include<iostream>
#include<string>
#include<vector>
#include<algorithm>
#include<queue>

using namespace std;

int main(){
    long long N,H;
    cin>>N>>H;
    vector <long long>a(N);
    vector <long long>b(N);
    for(int i=0 ; i<N ; i++){
        cin>>a[i];
        cin>>b[i];
    }
    
    long long a_m;
    long long ans=0;
    sort(a.begin(),a.end());
    sort(b.begin(),b.end());
    a_m=a[N-1];
    
    for(long long i=N-1 ; i>0 ; i--){
        f(a_m<=b[i]){
            H-=b[i];
            ans+=1;
        }
        if(H<=0){
            break;
        }
    }
    if(H>0){
        while(1){
            ans+=1;
            H-=a_m;
            if(H<=0)break;
        }
    }
    cout<<ans<<endl;
    return 0;
}
