import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner koko = new Scanner(System.in);
        int[] a = new int[3];
        for(int i=0; i<3; i++){
            a[i]=koko.nextInt();
        }
        Arrays.sort(a);
        int number=a[0];
        for(int i=0; i<3; i++){
            a[i]=a[i]-number;
        }
        while(a[2]>=3&&a[1]>=1){
            a[2]=a[2]-3;
            a[1]=a[1]-1;
            number++;
            Arrays.sort(a);
        }
        System.out.println(number);
    }
}