Series=40-38+36-........n

Series=40-38+36-........n

 

 

//Series=40-38+36-........n

#include<stdio.h>

int main(){

    int n,sum,increase,term;

    scanf("%d",&n);

    sum=0;

    increase=40;

    for(term=0;term<n;term++){

        if(term%2==0)

            sum+=increase;

        else

            sum-=increase;

        increase-=2;

    }

    printf("The summation of the series id %d\n",sum);

    return 0;

}