#include <stdio.h>

int main() {
    long long n = 0;
    scanf("%lld",&n);
    if(n <= 12)
    {
        printf("2\n");
    }
    else {
    long long n1 = (n / 12) * 4;
    long long time = n1 + 2;
    printf("%lld\n",time);
    }
    
    return 0;
}