#include <iostream>
#include <cstdio>
#include <algorithm>
using namespace std;
int n, h, a[100005], b[100005], ma, sb, ans;
int main() {
	int i;
	scanf("%d%d", &n, &h);
	for(i=0; i<n; i++) {
		scanf("%d%d", &a[i], &b[i]);
		ma = max(ma, a[i]);
	}
	sort(b, b+n);
	for(i=n-1; i>=0; i--) {
		ans++;
		h -= max(b[i], ma);
		if(h<=0) break;
	}
	if(h>0) {
		ans += (h+ma-1)/ma;
	}
	cout<<ans;
	return 0;
}