#include <stdio.h>
#include <math.h>

int minTurnsRecursive(int score) {
    if (score == 0) {
        return 0;
    }
    if (score == 1 || score == 2 || score == 3) {
        return 1;
    }
    int option1 = 1 + minTurnsRecursive(score - 1);
    int option2 = 1 + minTurnsRecuesive(score - 2);
    int option3 = 1 + minTurnsRecuesive(score - 3);
    
    int min_options = option1;
    if (option2 < min_options) {
        min_options = option2;
    }
    if (option3 < min_options) {
        min_options = option3;
    }
    return min_options;
}
int main() {
    float n;
    if (scanf("%f", &n) != 1) {
        printf("Invalid Input\n");
    } else {
        int score = (int)round(n);
        int turns = minTurnsRecuesive(score);
        printf("%d\n", turns);
    }
    return 0;
}