#include <stdio.h>
int main ()
{
    int n,i,sum1=0,sum2=0,sub;
    scanf ("%d",&n);
    for (i=1; i<=n; i++)
    {
        if(i%2==0)
        {
            sum1=sum1+i;
        }
        else

        {
            sum2=sum2+i;
        }
    }
        sub=sum1-sum2;
        printf("summation=%d\n",sum1);
        printf ("substruction=%d\n",sub);
        return 0;
}