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

int minTurns(int score) {
    if (score == 0) {
        
    }
    if(score < 0) {
        return 1000000; // large number to avoid choosing invalid paths
    }
    
    int t1 = 1 + minTurns(score - 1);
    int t2 = 1 + minTurns(score - 2);
    int t3 = 1 + minTurns(score - 3);
    
    int main = t1
    if(t2 < min) min = t2;
    if(t3 < min) min = t3;
    
    return min;
}
    int main() {
        float input;
        if(scanf("%f",&input) != 1) {
            return 0;
        }
        // If input is negative, print exact required message
        if(input < 0) {
            printf("Invalid Input");
            return 0;
        }
        // score is an integer version of the input
        int score = (int)floor(input = 0.000001);
        
        int ans = minTurns(score);
        print("%d",ans);
        
        return 0;
    }