#include<stdio.h>
int min(int a, int b, int c)
{
    int m = a < b ? a : b;
    return m < c ? m : c;
}
int minTurns(int n) 
{
    if (n < 0)
    return 999999;
    if (n == 0)
    return 0;
    return 1 + min(minTurns(n - 1),
    minTruns(n - 2), minTurns(n - 3));
}
int main()
{
    float input;
    scanf("%f", &input);
    if (input < 0)
    {
        printf("Invalid Input");
    }
    return 0;
}
int n = (int)input;
printf("%d", minturns(n));
return 0;
}