x, N = map(int, input().split())
A = list(map(int, input().split()))
A += [0]
A.sort()

mod = 10 ** 6 + 3
ans, tmp = 0, 1

for i in range(1, len(A)):
    tmp *= pow(x, A[i] - A[i - 1], mod)
    tmp %= mod
    ans += tmp
    ans %= mod

print(ans)