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