#include <bits/stdc++.h>
using namespace std;

#define ui long long

int main() {
    ui n,h;
    cin>>n>>h;
    ui a[n],b[n];
    for (ui i = 0; i < n; ++i) {
        cin>>a[i]>>b[i];
    }
    sort(a,a+n);
    sort(b,b+n);
    ui count=0,i=n-1;
    while(b[i]>=a[n-1]){
        count++;
        h-=b[i];
        i--;
        if(h<=0)goto endp;
        if(i<0)break;
    }
    count+=h/a[n-1];
    if(h%a[n-1]!=0)count++;
    endp:;
    cout<<count<<endl;
    return 0;
}