#include<stdio.h>
int minturns(int score)
{
    if(score==0)
    return 0;
    if(score<0)
    return 9999;
    int a = minturns(score - 1);
    int b = minturns(score - 2);
    int c = minturns(score - 3);
    int min = a;
    if(b<min) min = b;
    if(c<min) min = c;
    return 1+min;
}
int main()
{
    float input;
    scanf("%f",&input);
    if(input<0)
    {
        printf("Invalid input");
        return 0;
    }
    int score = (int)input;
    int result = minturns(score);
    printf("%d",result);
    return 0;
}
    
    
    
   
    return 0;
}