using ull = unsigned long long;
ull p(long a){
  ull res;
  if (a<0) return 0;
  if (a==0 || a==1) return 1;
  return p(a-1)+p(a-2)-p(a-5)-p(a-7);
}
ull exp_sum(unsigned int n) {
  return p(n);
}