#include<iostream>
#include<algorithm>
#include<vector>
using namespace std;
int main(void)
{
    int n,h,b,d;
    vector<int> a,b;
    cin>>n>>h;
    for(int i=0;i<n;i++){
        cin >> c;
        cin >> d;
        a.push_back(c);
        b.push_back(d);
    }
    sort(a.begin(),a.end(),greater<int>());
    sort(b.begin(),b.end(),greater<int>());
    int e[n]={};
    int ecount = 0;
    for(int i=0;i<n;i++)
    {
        if(b[i]>=a[0])
        e[i]=b[i]
        ecount+=1;
    }
    int esum = 0;
    for(int i=0;i<ecount;i++)
    {
        esum+=e[i;]
    }
    int count = 0;
    while(h<=esum)
    {
        h-=a[0];
        count+=1;
    }
    while(1)
    {
        h-=e[i];
        count+=1;
        if(h<=0)
        break;
    }
    cout<<count;
    return 0;
}

