#include <bits/stdc++.h>
#define ll long long
using namespace std;

const ll mod = 1e9 + 7;

ll mul(ll a, ll b){
    if(!(b ^ 0ll))
        return 0;
    ll t = mul(a, b >> 1) % mod;
    if(b & 1ll)
        return ( (t << 1) % mod + (a % mod) ) % mod;
    return (t << 1) % mod;
}

ll reverse_modulo(ll v){
    ll a = v, b = mod, r, q;
    ll xa = 1, xb = 0, xr;
    while(b != 0){
        q = a / b;
        r = a - q * b;
        xr = xa - q * xb;
        a = b;
        xa = xb;
        b = r;
        xb = xr;
    }
    return (xa + mod) % mod;
}

int main()
{
    ll n, k;
    cin >> n >> k;
    if(k > ((n + 1) >> 1))
        cout << '0';
    else{
        ll ans = 1, gt = 1;
        for(ll i = 0; i < k; ++i){
            ans = mul(ans, n - ((k - 1ll) << 1) + i);
            gt = gt * (i + 1ll) % mod;
        }
        ans = mul(ans, reverse_modulo(gt));
        cout << ans;
    }
}