package yukicorder;

import java.util.Scanner;


//TODO 見直し
public class No_91 {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int r = sc.nextInt();
		int g = sc.nextInt();
		int b = sc.nextInt();

		System.out.println(solve(r,g,b));
	}

	public static int solve(int r, int g, int b){
		int basic = Math.min(Math.min(r,g),b); //各石の最低値
		int red = r - basic;
		int green = g - basic;
		int blue = b - basic;
		int acce = basic; //暫定的なアクセサリーの数は変数basic


		while(true){
			if(red == 0){
				if(Math.max(green, blue) > 2){
					if(blue > green){
						blue -= 2;
					}else{
						green -= 2;
					}
				}else{
					break;
				}
				red++;
			}
			if(green == 0){
				if(Math.max(red, blue) > 2){
					if(blue > red){
						blue -= 2;
					}else{
						red -= 2;
					}
				}else{
					break;
				}
				green++;
			}
			if(blue == 0){
				if(Math.max(red, green) > 2){
					if(red > green){
						red -= 2;
					}else{
						green -= 2;
					}
				}else{
					break;
				}
				blue++;
			}
			red--;
			green--;
			blue--;
			acce++;
		}

		return acce;
	}
}