How many ways are there to choose two distinct positive integers totaling N, disregarding the order?
N = int(input())

if N % 2 == 1:
    ans = (N + 1) / 2 - 1

else:
    ans = N / 2 - 1

print(ans)
N = int(input())

if N % 2 == 1:
    ans = (N - 1) / 2

else:
    ans = N / 2 - 1

print(int(ans))