#include<stdio.h>
int main()
{
    float score;
    scanf("%f",&score);
    if(score<0)
    {
        printf("Invlaid input");
        
    }
    else 
    {
        int intscore=(int)score;
        int turns=intscore/3;
        int remainderintscore%3;
        if(remainder !=0)
    }
    turns+=1;
    }
    printf("%d",turns);
    }
    return 0;
}