View Code of Problem 18

#include<stdio.h>
#include<string.h>
#include<math.h>
#include<stdlib.h> 
int main()
{
	int i,n;
	while(scanf("%d",&n)!=EOF)
	{
		int k=0,sum=0;
		for(i=1;i<=n;i++)
		{
			sum=sum+k;
			if(i%2==0) k++;
		}
		printf("%d\n",sum);
	}
	
	return 0;
 }