N,K = map(int,input().split())
if K == 1:
    print("0")
    exit()
else:
    print(N - K) N,K = map(int,input().split()) N map(int,input().split()) map int input().split() ().split () input split K if K == 1:
    print("0")
    exit()
else:
    print(N - K) K == 1 K 1 print("0") print "0" exit() exit print(N - K) print N - K N K 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("0")
    exit()
else:
    print(N - K)