#include <bits/stdc++.h>
using namespace std;
template <class T>
T gcd(T a, T b) {
  return b == 0 ? a : gcd(b, a % b);
}
template <typename T>
T lcm(T a, T b) {
  return a / gcd(a, b) * b;
}
template <class T>
T my_pow(T n, T p) {
  if (p == 0) return 1;
  T x = my_pow(n, p / 2);
  x = (x * x);
  if (p & 1) x = (x * n);
  return x;
}
template <class T>
T big_mod(T n, T p, T m) {
  if (p == 0) return (T)1;
  T x = big_mod(n, p / 2, m);
  x = (x * x) % m;
  if (p & 1) x = (x * n) % m;
  return x;
}
template <class T>
T extract(string s, T ret) {
  stringstream ss(s);
  ss >> ret;
  return ret;
}
string itos(long long n) {
  string s;
  while (n) {
    s += (n % 10 + 48);
    n /= 10;
  }
  reverse(s.begin(), s.end());
  return s;
}
long long stoi(string s) {
  long long n = 0;
  for (__typeof(s.size()) i = 0; i < (s.size()); i++) n = n * 10 + (s[i] - 48);
  return n;
}
long long ar[1000005], br[100001];
long long a = 0, b = 0, c = 0, r = 0, rr = 0, res = 0, n, m, t = 0, ks = 0, w;
string s;
long long MOD = 1e6 + 3;
int main() {
  ar[0] = 1;
  for (__typeof(1000003) i = 1; i <= (1000003); i++)
    ar[i] = (ar[i - 1] * i * 1LL) % MOD;
  cin >> n >> m;
  m--;
  for (__typeof(n) i = 1; i <= (n); i++) {
    long long aa = ar[i + m];
    long long bb = ar[i];
    long long cc = ar[m];
    long long dd = (cc * bb) % MOD;
    r = r + (aa) * (big_mod(dd, MOD - 2, MOD));
    r %= MOD;
  }
  cout << r;
  return 0;
}
