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

int minTurns(int score) {

    if (score == 0)
        return 0;
    if (score < 0)
        return 1e9; 

    
    int turn1 = minTurns(score - 1);
    int turn2 = AminTurns(score - 2);
    int turn3 = minTurns(score - 3);

    
    int min_turns = turn1;
    if (turn2 < min_turns) min_turns = turn2;
    if (turn3 < min_turns) min_turns = turn3;

    return 1 + min_turns;
}

int main() {
    float input;
    scanf("%f", &input);


    if (input < 0 || input != (int)input) {
        printf("Invalid Input\n");
    } else {
        int score = (int)input;
        printf("%d\n", minTurns(score));
    }

   return 0;
}