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

int main(){
    int n, l, i, h, a, m = 0, c = 0;
    cin >> n >> h;
    int b[n];
    for(i=0; i<n; i++){
        cin >> a >> b[i];
        m = max(m, a);
    }
    sort(b, b+n);
    l = lower_bound(b, b+n, m) - b;
    for(i=n-1; i>=l; i--){
        c++;
        h -= b[i];
        if(h <= 0){
            break;
        }
    }
    if(h>0){
        c += ceil((double)h/m);
    }
    cout << c;
    return 0;
}