static ZZ choose1(int n, int k) { assert(k < 1e7); if (n < k) return 0; if (k == 0) return 1; return choose1(n-1, k-1) * n / k; }
int main() { int c1 = choose1(5,10); int c2 = choose2(0,c1); return c1+c2; }