#include<stdio.h>
#include<limits.h>
int minTurns(int n){
    if(n==0)
    return 0;
        if(n == 0)
        return INT_MAX;
        
        int a = 1 + minTurns(n - 1);
        int b = 1 + minTurns(n - 2);
        int c = 1 + minTurns(n - 3);
        
        int min =a;
        if(b < min) min = b;
         if(c < min) min = c;
         return min;
}
    int main(){
        float score;
        scanf("%f",&score);
        if(score < 0){
            printf("Invalid Input");
            return 0;
        }
    
    int n =(int)score;
    int result=min;
    printf("%d",result);
    
    return 0;
    }