N,H = map(int,input().split())
A = [list(map(int,input().split())) for _ in range(N)]
A = sorted(A,key=lambda x:x[1], reverse=True)
A = sorted(A,key=lambda x:x[0],reverse=True)
cnt = 0
tot = 0
ind = 0
a = A[0][0]
b = A[0][1]
for i in range(1,N):
    if A[i][1]>=a:
        tot += A[i][1]
        cnt += 1
    if tot>=H:
        ind = 1
        break
if ind == 0:
    tot += b
    cnt += 1
    if tot<H:
        if (H-tot)%a==0:
            cnt += (H-tot)//a
        else:
            cnt += (H-tot)//a+1
print(cnt)