(A[0] c A[1], A[2] c A[3] и т. д.)

x = input().split()
x1 = []
n = 1
for i in range(1, len(x) - 1):
    if n <= len(x):
        x[n], x[i] = x[i], x[n]
        n += 1
        x1.append(x[n] + x[i])
print(' '.join(x1))

a = [int(i) for i in input().split()]
for i in range(1, len(a), 2):
    a[i - 1], a[i] = a[i], a[i - 1]
print(' '.join([str(i) for i in a]))