#include <bits/stdc++.h>
using namespace std;
const int MAX_N = 1e5 + 5, MOD = 1e9 + 7;
long long factorial[MAX_N + 5], inverse_factorial[MAX_N + 5];
long long power(long long x, long long p) {
  long long result = 1;
  while (p) {
    if (p % 2 == 1) result = (result * x) % MOD;
    x = (x * x) % MOD;
    p /= 2;
  }
  return result;
}
void precompute() {
  factorial[0] = 1;
  for (int i = 1; i <= MAX_N; i++) {
    factorial[i] = (i * factorial[i - 1]) % MOD;
  }
  inverse_factorial[MAX_N] = power(factorial[MAX_N], MOD - 2);
  for (int i = MAX_N - 1; i >= 0; i--) {
    inverse_factorial[i] = ((i + 1) * inverse_factorial[i + 1]) % MOD;
  }
}
long long combinations(long long n, long long k) {
  if (n < k) {
    return 0;
  }
  long long numerator = factorial[n];
  long long denominator_inverse =
      (inverse_factorial[k] * inverse_factorial[n - k]) % MOD;
  return (numerator * denominator_inverse) % MOD;
}
int main() {
  precompute();
  int n, length;
  cin >> n >> length;
  long long answer = combinations(n + 2 * length - 1, 2 * length);
  cout << answer << "\n";
  return 0;
}
