n, k = list(map(int, input().split()))

if(k==1):
  print(0)
else:
  print(n-k) n, k = list(map(int, input().split())) n list(map(int, input().split())) list map(int, input().split()) map int input().split() ().split () input split k if(k==1):
  print(0)
else:
  print(n-k) k==1 k 1 print(0) print 0 print(n-k) print n-k n k n, k = list(map(int, input().split())) list(map(int, input().split())) n k = list(map(int, input().split())) list(map(int, input().split())) k
n, k = list(map(int, input().split()))

if(k==1):
  print(0)
else:
  print(n-k)