#include<stdio.h>
int minTurns(int n)
{
    if(n==0)return 0;
    if(n<0)return 999999;
    int a = minTurn(n-1);
    int b = minTurn(n-2);
    int c = minTurn(n - 3);
    int min = a; 
    if(b < min) min = b;
    if(c < min)min = c;
    return min + 1;
}
int main ()
{
    int n;
    if(scanf("%d",&n)!=1 || n<0)
{
    printf("Invalid input");
    return 0;
}
printf("%d",minTurbn(n));
return 0;
}