// editor1
#include<stdio.h>
#include<math.h>
int minTurns(int score){
    if(score==0)
    return 0;
    if(score<0)
    return 1000;
    int turn1=mnTurns(score - 1);
    int turn2=mnTurns(score - 2);
    int turn3=mnTurns(score - 3);
    int min=turn1;
    if(turn2<min)
    min=turn2;
    if(turn3<min)
    min=turn3;
    return 1+min;
}
int main(){
    float input;
    scanf("%f",&input);
    int score=(int)round(input);
    if(score<0){
        printf("Invalid Input\n");
    }
    else{
        printf("%d\n",minTurns(score));
        
    }
    return 0;
}