# 2016.2.12

N = input()
alpha = [0 for i in range(0, N)]
beta = [0 for i in range(0, N)]
alpha[0] = 4
alpha[1] = 2
beta[0] = 4
beta[1] = 2
if N < 3:
    print "0"
else:
    for i in xrange(3, N):
        beta[0] += alpha[0]
        beta[1] += alpha[0] * (i - 1)
        for j in xrange(1, i-1):
            tmp = alpha[j]
            beta[j-1] += tmp * j
            beta[j] += tmp
            beta[j+1] += tmp * (i - 1 - j)
        alpha = [be for be in beta[0:N]]
    print alpha[0] % 1000000007