#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;
}