#include<bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i=0;i<n;i++)
int main(){
    int n,a[200000],b[200000],ans=0;
    double h;
    cin>>n>>h;
    rep(i,n) cin>>a[i]>>b[i];
    sort(a,a+n,greater<int>());
    sort(b,b+n,greater<int>());
    for(int i=0;a[0]<=b[i]&&h>0;i++) h-=b[i],ans++;
    if(h<=0) cout<<ans;
    else cout<<ans+int(ceil(h/a[0]));
}