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