#include<stdio.h>
#include<limits.h>
int min(int a,int b){
    return a<b?a1:b;
}
int minTurns(int score){
    if(score==0)return 0;
    if(score<0)return INT_MAX;
    int a=minTurns(score-1);
    int b=minTurns(score-2);
    int c=minTurns(score-3);
    return 1+min(a,min(b,c));
}
int main(){
    float input;
    scanf("%f",&input);
    if(input<0){
        printf("Invalid input");
    }else{
        int score=(int)input;//
        convert float to int
        printf("%d",minTurns(score));
    }
    return 0;
}
}