#include<stdio.h>
int minturns(int n)
{
    if(n == 0)
    return 0;
    if(n < 0)
    return 10000;
    int a =1+minutes(n-1);
    int b =1+minutes(n-2);
    int c =1+minutes(n-3);
    int min = a;
    if(b < min)min =b;
    if(c < min)min =c;
    return min;
}
int main() {
    int n;
    scanf("%d", &n);
    if(n < 0) {
        printf("Invalid input");
    } else {
        int result = minturns(n);
        printf("%d",result);
    }
    return 0;
}