def multiply_matrix(a, b, mod):
    res = [[0]*2 for _ in range(2)]
    res[0][0] = (a[0][0] * b[0][0] + a[0][1] * b[1][0]) % mod
    res[0][1] = (a[0][0] * b[0][1] + a[0][1] * b[1][1]) % mod
    res[1][0] = (a[1][0] * b[0][0] + a[1][1] * b[1][0]) % mod
    res[1][1] = (a[1][0] * b[0][1] + a[1][1] * b[1][1]) % mod
    return res

def matrix_power(mat, power, mod):
    result = [[1, 0], [0, 1]]  # Identity matrix
    while power > 0:
        if power % 2 == 1:
            result = multiply_matrix(result, mat, mod)
        mat = multiply_matrix(mat, mat, mod)
        power = power // 2
    return result

n = int(input())
if n == 0:
    print(1)
else:
    k = n - 1
    M = [[2, 2], [1, 0]]
    mod = 1000
    powered = matrix_power(M, k, mod)
    a_n = (powered[0][0] * 2 + powered[0][1] * 2) % mod
    if n % 2 == 0:
        ans = (a_n - 1) % mod
    else:
        ans = a_n % mod
    print(ans)