#include<iostream.h>
void main()
{
int n=0,i,s=0,sc=0;
cout<<"n:";cin>>n;
for(i=1;i<=n;i++)
{
if(i%2==0)
cout<<"-";
else
cout<<"+";
if(i%2==0)
{
s=s-i*(i+1);
cout<<i<<"*"<<(i+1);
}
else
{
s=s+i*(i+1);
cout<<i<<"*"<<(i+1);
}
sc=sc+s;
s=0;
}
cout<<"="<<sc;
}