n,h = map(int, input().split())
p = 0
q = []
for i in range(n):
    a,b = map(int, input().split())
    p = max(p,a)
    q.append(b)
ans = 0
q.sort(reverse=True)
i = 0
while h>0:
    if p<q[i]:
        h -= q[i]
        i +=1
        ans +=1
        if i==n:
            break
    else:
        break
if h%p==0:
    ans += h//p
else:
    ans += h//p 
    ans +=1
print(ans)
