#include <stdio.h>
void main(void){
	int n;
	scanf("%d",&n);
	int dayCount = 0;
	while(n != 0){
		dayCount++;
		if(dayCount/7 > 0 && dayCount%7 == 0){
			n= n+6;
		}
		n--;
	}
	printf("%d",dayCount);
}