#include <bits/stdc++.h> #define mp make_pair #define pb push_back using namespace std; typedef pair<int, int> pii; typedef long long ll; typedef unsigned long long ull; const double eps = 1e-7; const double pi = acos(-1.0); const int inf = 0x3f3f3f3f; inline ll read() { ll f = 1, x = 0; char c = getchar(); while(c < '0' || c > '9') { if(c == '-') f = -1; c = getchar(); } while(c >= '0' && c <= '9') { x = (x << 1) + (x << 3) + (c ^ 48); c = getchar(); } return f * x; } const int mod = 1e9 + 7; const int N = 2e6 + 10; ll fac[N], inv[N]; ll qpow(ll a, int n) { ll ans = 1; while(n) { if(n & 1) ans = (ans * a) % mod; a = (a * a) % mod; n >>= 1; } return ans; } ll C(int n, int m) { if(n < 0 || m < 0 || m > n) return 0; if(m == 0 || m == n) return 1; return ((fac[n] * inv[m]) % mod * inv[n - m]) % mod; } void init() { fac[0] = 1; for(int i = 1; i < N; i++) fac[i] = (fac[i - 1] * i) % mod; inv[N - 1] = qpow(fac[N - 1], mod - 2); for(int i = N - 2; i >= 0; i--) inv[i] = (inv[i + 1] * (i + 1)) % mod; } int main() { // freopen("in.txt", "r", stdin); // freopen("out.txt", "w", stdout); // ios::sync_with_stdio(false), cin.tie(0), cout.tie(0); init(); while(true) { int n = read(), m = read(); printf("%lld\b", C(n, m)); } return 0; }