N,H = map(int,input().split())
A = []
B = []
for i in range(N):
    a,b = map(int,input().split())
    A.append(a)
    B.append(b)

import numpy
A = numpy.array(A)
B = numpy.array(B)
AsortA = numpy.sort(A)[::-1]
BsortB = numpy.sort(B)[::-1]

ans = 0
maxattack = AsortA[0]
throw = BsortB[maxattack < BsortB]
if(sum(throw) >= H):
    for i in range(1,len(throw) + 1):
        if(sum(throw[:i]) >= H):
            ans = i
            break
else:
    resH = H - sum(throw)
    ak = int(numpy.ceil(resH/maxattack))
    ans = ak + len(throw)
    
print(ans)