#include <stdio.h>

int main()
{

    int i; //counter for the loop
    int n; //integer
    int series;

    printf("Enter an integer number: ");
    scanf("%d" , &n);

        for(i = 1; i <= n; i++)
    {
        if (i % 2 == 0)
        (series -= i * i);
    else
        (series += i * i);
}
    printf("The value of the series is: %dn" , series);

return 0;
}