#include<bits/stdc++.h>
using namespace std;
	
	int n,v,ans,a[100005],b[100005];
int main()
{
    std::ios::sync_with_stdio(false);
    cin>>n>>v;
    for (int i=1;i<=n;i++) 
	cin>>a[i]>>b[i];
    sort(a+1,a+n+1);
    sort(b+1,b+n+1);
    for(int i=n;i>=1&&b[i]>a[n]&&v>0;v-=b[i],i--,ans++);
    if(v>0) ans=ans+v/a[n]+(v%a[n]!=0);
    cout<<ans;
}