#include<cstdio>
#include<algorithm>
#define int long long int
using namespace std;

int a[200000], b[200000];
 main(void) {
    int n,h;
    scanf("%lld%lld",&n,&h);
    for(int i=0; i<n; i++)
        scanf("%lld%lld",&a[i],&b[i]);
    int m = 0;
    for(int i=0; i<n; i++)
        if(m < a[i]) m = a[i];
    sort(b, b+n);

    int res = (h+m-1)/m;
    long long int t = 0;
    for(int i=0; i<n; i++) {
        t += b[n-1-i];
        int k = (h-t+m-1)/m + (i+1);
        if(k < res) res = k;
    }
    printf("%lld\n", res);
}
