#include <bits/stdc++.h>   using namespace std;   long long mod = 1000000007;   long long power(long long x, int y) {     long long res = 1;     x = x % mod;     if (x == 0) return 0;     while (y > 0) {       if (y & 1) res = (res * x) % mod;       y = y >> 1;       x = (x * x) % mod;     }     return res;   }   int modInverse(long long a) { return power(a, mod - 2); }   long long factmod(long long a) {     long long val = 1;     while (a > 0) {       val = (val * a) % mod;       a--;     }     return val;   }   int main() {     ios_base::sync_with_stdio(0);     cin.tie(0);     cout.tie(0);     long long n, m, ans;     cin >> n >> m;     ans = (factmod(n + 2 * m - 1) * modInverse(factmod(2 * m)) % mod *            modInverse(factmod(n - 1) % mod)) %           mod;     cout << ans;   }   