#include <bits/stdc++.h>
using namespace std;
const long long mod = 1e9 + 7;
template <class T>
inline T read() {
  T x = 0, f = 1;
  char s = getchar();
  while (s < '0' || s > '9') {
    if (s == '-') f = -1;
    s = getchar();
  };
  while (s >= '0' && s <= '9') {
    x = (x << 3) + (x << 1) + s - 48;
    s = getchar();
  };
  return x * f;
}
template <typename T>
inline void wri(T x) {
  if (x < 0) {
    x = -x;
    putchar('-');
  };
  if (x / 10) wri(x / 10);
  putchar(x % 10 + 48);
}
template <typename T>
inline void print(T x, char s) {
  wri(x);
  putchar(s);
}
template <typename T>
T gcd(T a, T b) {
  return b == 0 ? a : gcd(b, a % b);
}
long long C[1010][15];
long long cal(int n, int m) {
  if (C[n][m] || n == 0)
    return C[n][m];
  else {
    for (register int i = (0); i < (m + 1); i++) {
      if (i == 0)
        C[n][m] = (C[n][m] + 1) % mod;
      else {
        C[n][m] = (C[n][m] + cal(n - 1, i)) % mod;
      }
    }
  }
  return C[n][m];
}
long long cnt;
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0), cout.tie(0);
  int n, m;
  cin >> n >> m;
  for (register int i = (1); i < (m + 1); i++) C[1][i] = 1;
  for (register int i = (1); i < (n + 1); i++) {
    cnt =
        ((cnt + ((cal(i, m) - cal(i - 1, m) + mod) % mod * cal(n - i + 1, m))) %
         mod) %
        mod;
  }
  cout << cnt;
  return 0;
}
