9 530792195 6
 0 0 10
 1944219055 454183506 1369298327
 914835 2742837 9234739
 10 10 0
 2 2 0
 0 0 1
 3 10 1007169359
 0 1 0
 1016450951 2 9
 0 2 10
 2147483648 0 2147483647
 92134834 23742837 92374738
 1 4 3
 382601556 881329640 791556039
 0 0 58
 5 10 6
 10 6 8
 6 8 10
 3 2 0
 1 4 4
 2147483630 2147483642 2147483610
 1 0 0
 18 67 5
 50606342 2 1134945035
 8 97 83
 2147483648 0 0
 92134834 23742837 92374737
 5 0 5
 772486757 1747374885 377299255
 1 0 1
 1 2 3
 0 3 2
 2147483648 2147483647 2147483648
 51 10 91
 9214834 2742837 9234739
 1 2 2147483648
 67 81 1
 92134834 23742837 92374739
 2 7 95
 3 0 2
 5 9 0
 1 10 2
 246543403 71853598 1504509195
 2147483648 2147483648 2147483648
 48 6 7
 2147483648 2147483648 0
 1358352906 27037371 1947040615

                                                       530792195
                                                                0
                                                       1944219055
                                                          2742837
                                                               10
                                                                2
                                                                0
                                                       1007169359
                                                                0
                                                       1016450951
                                                                2
 2147483648                                                         92374738
                                                                3
                                                        881329640
                                                                0
                                                               10
                                                                8
                                                                8
                                                                2
                                                                4
                                                       2147483630
                                                                0
                                                               67
                                                         50606342
                                                               97
                                                                0
                                                         92374737
                                                                5
                                                        772486757
                                                                1
                                                                3
                                                                2
 2147483648                                                               91
                                                          9234739
 2147483648                                                               67
                                                         92374739
                                                               95
                                                                2
                                                                9
                                                               10
                                                       1504509195
 2147483648                                                               48
 2147483648                                                       1947040615

import java.util.*;

    public class Test_Project_0001 
    {
        public static void main(String[] args)
        {
            Scanner sc = new Scanner(System.in);
            
            int R = sc.nextInt();
            int G = sc.nextInt();
            int B = sc.nextInt();
            int count = 0;
            
            while((R!=0 && G!=0)||(R!=0 && B!=0)||(G!=0 && B!=0))
            {
                
                if(R == G)
                {
                    B += R;
                    count += R;
                    R = G = 0;
                    //System.out.println("1");
                }
                else if(G == B)
                {
                    R += G;
                    count += G;
                    G = B = 0;
                    //System.out.println("2");
                }
                else if(B == R)
                {
                    G += B;
                    count += B;
                    R = B = 0;
                    //System.out.println("3");
                }
                if(R < G && R < B)
                {
                    if(G > B && (B-R)%2 == 0) 
                    {
                        count += B;
                        R = B = 0;
                        //System.out.println("4");
                    }
                    else if (B > G && (G-R)%2 == 0) 
                    {
                        count += G;
                        R = B = 0;
                        //System.out.println("5");
                    }
                    else if(G > B && (G-R)%2 == 0 && (G-R)/2 < B) 
                    {
                        count += G;
                        R = B = 0;
                        //System.out.println("6");
                    }
                    else if (B > G && (B-R)%2 == 0 && (B-R)/2 < G) 
                    {
                        count += B;
                        R = B = 0;
                        //System.out.println("7");
                    }
                    else if(G > B)
                    {
                        if(B!=1)
                        {
                        count+=B/2;
                        R += B/2;
                        G -= B/2;
                        B -= B/2;
                        }
                        else
                        {
                        count+=1;
                        R += 1;
                        G -= 1;
                        B -= 1;                        
                        }
                        //System.out.println("8");
                        //System.out.println(R + " " + G + " " + B);
                    }
                    else
                    {
                        if(G!=1)
                        {
                        count+=G/2;
                        R += G/2;
                        G -= G/2;
                        B -= G/2;
                        }
                        else
                        {
                        count+=1;
                        R += 1;
                        G -= 1;
                        B -= 1;                        
                        }
                        //System.out.println("8-2");
                        //System.out.println(R + " " + G + " " + B);
                    }
                }
                if(G < R && G < B)
                {
                    if(R > B && (B-G)%2 == 0) 
                    {
                        count += B;
                        R = B = 0;
                        //System.out.println("9");
                    }
                    else if(B > R && (R-G)%2 == 0) 
                    {
                        count += R;
                        R = B = 0;
                        //System.out.println("10");
                    }
                    else if(R < B && (B-G)%2 == 0 && (B-G)/2 < B) 
                    {
                        count += B;
                        R = B = 0;
                        //System.out.println("11");
                    }
                    else if(B < R && (R-G)%2 == 0 && (R-G)%2 < R) 
                    {
                        count += R;
                        R = B = 0;
                        //System.out.println("12");
                    }
                    else if(R < B)
                    {
                        if(R!=1)
                        {
                        count+=R/2;
                        R -= R/2;
                        G += R/2;
                        B -= R/2;
                        }
                        else
                        {
                        count+=1;
                        R -= 1;
                        G += 1;
                        B -= 1;                        
                        }
                        //System.out.println("13");
                        //System.out.println(R + " " + G + " " + B);
                    }
                    else
                    {
                        if(B!=1)
                        {
                        count+=B/2;
                        R -= B/2;
                        G += B/2;
                        B -= B/2;
                        }
                        else
                        {
                        count+=1;
                        R -= 1;
                        G += 1;
                        B -= 1;
                        
                        }
                        //System.out.println("14");
                        //System.out.println(R + " " + G + " " + B);
                    }
                }
                if(B < G && B < R)
                {
                    if(G > R && (R-B)%2 == 0) 
                    {
                        count += R;
                        R = B = 0;
                        //System.out.println("15");
                    }
                    else if(R > G && (G-B)%2 == 0) 
                    {
                        count += G;
                        R = B = 0;   
                        //System.out.println("16");
                        //System.out.println(R + " " + G + " " + B);
                    }
                    else if(G < R && (R-B)%2 == 0 && (R-B)/2 < R) 
                    {
                        count += R;
                        R = B = 0;
                        //System.out.println("17");
                    }
                    else if(R < G && (G-B)%2 == 0 && (G-B)/2 < G) 
                    {
                        count += G;
                        R = B = 0;   
                        //System.out.println("18");
                    }
                    else if(R < G)
                    {
                        if(R!=1)
                        {
                        count+=R/2;
                        R -= R/2;
                        G -= R/2;
                        B += R/2;
                        }
                        else
                        {
                        count+=1;
                        R -= 1;
                        G -= 1;
                        B += 1;
                        
                        }
                        //System.out.println("19");
                    }
                    else
                    {
                        if(G!=1)
                        {
                        count+=G/2;
                        R -= G/2;
                        G -= G/2;
                        B += G/2;
                        }
                        else
                        {
                        count+=1;
                        R -= 1;
                        G -= 1;
                        B += 1;
                        }
                        //System.out.println("20");
                        //System.out.println(R + " " + G + " " + B);
                    }
                }
            }
            
            System.out.print(count);
        }
    }