#include<stdio.h>
int mainTurns(int n)
{
    if(n==0)return 0;
    if(n<0)return 999999;
    int a = minTurns(n-1);
    int b = minTurns(n-2);
    int c = minTurns(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",minTurns(n));
    return 0;
    }