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 K=list(map(int,input().split())) list(map(int,input().split())) K N,K=list(map(int,input().split())) list(map(int,input().split())) N
N,K=list(map(int,input().split()))

if K==1:
    print('0')
    
else:
    print(N-K)