#include<stdio.h>
int main()
{
    float s;
    int score;
    if(s<0)
    {
        printf("Invalid Input");
        return 0;
    }
    score=(int)s;
    int turns=0;
    while(score>0)
    {
        if(score>=3)
        {
            score-=3;
        }
        else if(score>=2)
        {
            score-=2;
        }
        else
        {
            score-=1;
        }
        turns++;
    }
    printf("%d\n",turns);
    return 0
}