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