#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
// Yukicoder №80 四角形を描こう ★★
// https://yukicoder.me/problems/no/88
// ***********************
#define PRINCR do{printf("\n");fflush(stdout);}while(0)
#define GETLINE(str) do{char *p;fgets(str,sizeof(str),stdin);p=strchr(str,'\n');if(p)*p='\0';}while(0)
#define REP(a,b) for(int a=0;a<(int)(b);++a)
static char *GETWORD(char* str) {char c;char *cp;cp=&str[0];c=fgetc(stdin);while( c != EOF ){if((c==' ')||( c=='\n')) break;*cp++=c;c=fgetc(stdin);}*cp='\0';return &str[0];}
#define	GETINTS(a,b) {char s[34];int *ap=a;REP(i,b){GETWORD(s);sscanf(s,"%d", ap);ap++;}}
static int GETLINEINT(void) {char s[34];GETLINE(s);return atoi(s);}
static int GETWORDINT(void) {char s[34];GETWORD(s);return atoi(s);}
#define SWAP(type,a,b) do{type _c;_c=a;a=b;b=_c;}while(0)
#define PI	  ((double)3.141592653589793238462643383279)
int main() {
	int	pencil;
	int	abc,ab,bc;

	pencil = GETWORDINT();
	abc = pencil /2;
	ab = abc /2;
	bc = abc - ab;
	printf("%d\n", ab * bc );
	return 0;
}