decl
    int n,i,j,sum,k;
enddecl
	read(n);
	sum=0;
	k=1;
	while(k≤n)do
		if(n≤1) then
			sum=sum+1;
		else
			i=1;
			j=1;
			while(i≤k)do
				j=j*i;
				i=i+1;
			endwhile;
			sum=sum+j;
		endif;
		k=k+1;
	endwhile;
	write(sum);