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