#include<stdio.h>

int main(void){

int N;
int i;
int counter=0;

scanf("%d",&N);

for(i=1;i<=N;i++){

if(i%3==0 && i%5==0)
counter=counter+4;

else if(i%3==0)
counter=counter+2;

else if(i%5==0)
counter=counter+2;

}

printf("%d",counter);


return 0;

}