#include <bits/stdc++.h>
using namespace std;
long long mod = 1e9 + 7;
long long Bpow(long long a, long long s) {
  if (s == 0) {
    return 1;
  }
  long long u = Bpow(a, s / 2);
  if (s & 1)
    return u * u % mod * a % mod;
  else
    return u * u % mod;
}
int32_t main() {
  long long n, m;
  cin >> n >> m;
  vector<vector<long long>> dpa(m, vector<long long>(n + 1));
  for (long long i = 1; i < n + 1; i++) {
    dpa[0][i] = dpa[0][i - 1] + 1;
  }
  for (long long i = 1; i < m; i++) {
    for (long long j = 1; j < n + 1; j++) {
      dpa[i][j] = (dpa[i - 1][j] + dpa[i][j - 1]) % mod;
    }
  }
  vector<vector<long long>> dpb(m, vector<long long>(n + 2));
  for (long long i = n; i > 0; i--) {
    dpb[0][i] = dpb[0][i + 1] + 1;
  }
  for (long long i = 1; i < m; i++) {
    for (long long j = n; j > 0; j--) {
      dpb[i][j] = (dpb[i - 1][j] + dpb[i][j + 1]) % mod;
    }
  }
  long long ans = 0;
  for (long long i = 1; i < n + 1; i++) {
    ans +=
        ((dpa[m - 1][i] - dpa[m - 1][i - 1]) + mod) % mod * dpb[m - 1][i] % mod;
    ans %= mod;
  }
  cout << ans;
}
