N,M=map(int, input().split())
A=[]
for i in range(N):
  x,y=map(int, input().split())
  A.append((x,y))
  
B=[]
for x,y in A:
  B.append((M-x)//y+1)

B=sorted(B)
ans=0
for i in range(len(B)):
  c=0
  ans=max(i//B[i]+1,ans)

print(ans)