#include <bits/stdc++.h>
using namespace std;
int N, H, amx, sum, ans;
priority_queue<int> pq;
int main(){
	scanf("%d %d", &N, &H);
	for(int i = 0; i < N; i++){
		int a, b;
		scanf("%d %d", &a, &b);
		pq.push(b);
		amx = max(a, amx);
	}
	while(!pq.empty()){
		if(pq.top() < amx)	break;
		sum += pq.top();
		pq.pop();
		ans++;
		if(sum >= H){
			printf("%d\n", ans);
			return 0;
		}
	}
	ans += ceil(1.0 * (H - sum) / amx);
	printf("%d\n", ans);
	return 0;
}