def closestNumbers(A):
    A.sort()
    D=[A[i+1] - A[i] for i in range(len(A)-1)]
    target=min(D)
    X=[[A[i],A[i+1] ]for i,d in enumerate(D) if d==target]
    for i in range(0,len(X)):
        print(X[i][0], X[i][1])