#include<stdio.h>
int main(int argc,char*argv[])
{
int n=0,rem,day=0;
scanf("%d",&n);
while(rem!=0)
{
rem=n/2-2;
day=day+1;
}
printf("%d\n",day);
return 0;
}
#include<stdio.h>
int main(int argc,char*argv[])
{
int n=0,rem,day=0;
scanf("%d",&n);
while(rem!=0)
{
rem=n/2-2;
day=day+1;
}
printf("%d\n",day);
return 0;
}