#include<cstdio>
#include<algorithm>
int a[100000], b[100000];
int main() {
	int n, h, i, damage = 0, num = 0;
	scanf("%d%d", &n, &h);
	for (i = 0; i < n; i++) {
		scanf("%d%d", &a[i], &b[i]);
	}
	std::sort(a, a + n);
	std::sort(b, b + n);
	i = n - 1;
	while (damage < h&&a[n - 1] < b[i]) {
		damage += b[i];
		i--;
		num++;
	}
	if (damage < h) {
		num += (h - damage) / a[n - 1];
		if ((h - damage) % a[n - 1] != 0) {
			num++;
		}
	}
	printf("%d", num);
	return 0;
}