int get_change(int m) {
  if(m <= 0)
  	return m;
  int change[] = {1,5,10};
  int start = 0;
  int n = 0;
  int temp;
  int max = 2;
  while(start < m){
  	  temp = start + change[max];
      if(temp <= m){
      	++n;
        start += change[max];
      }
      else{
      	if(max - 1 >= 0)
      		--max;
      }
  }
  return n;
}