n,h = (int(i) for i in input().split())
A,B = [],[]
for _ in range(n):
    a,b = [int(i) for i in input().split()]
    A.append(a)
    B.append(b)
a_max = max(A)
B.sort()[::-1]
power,ans = 0,0
for b in B:
    if a_max <= b:
        power += b
        ans += 1
        if power>=h: break
if power>=h:
    print(ans)
else:
    h -= power
    ans += h//a_max
    if h%a_max == 0: print(ans)
    else: print(ans+1)
