import java.io.*;
import java.util.*;

class Main {
	
	public static void out (Object o) {
		System.out.println(o);
	}
	
	public static void main (String[] args) throws IOException {
		BufferedReader br = 
			new BufferedReader(new InputStreamReader(System.in));
		
		String[] line = br.readLine().split(" ");
		int[] stones = new int[3];
		stones[0] = Integer.parseInt(line[0]);
		stones[1] = Integer.parseInt(line[1]);
		stones[2] = Integer.parseInt(line[2]);
		
		Arrays.sort(stones);
		
		int ans = 0;
		ans += stones[0];
		stones[1] -= stones[0];
		stones[2] -= stones[0];
		stones[0] = 0;
		
		if (stones[1] == stones[2]) {
			int m = stones[1] % 4;
			int n = stones[1] / 4 * 2;
			ans += m == 3 ? n + 1 : n;
		} else if (stones[0] != 0 && stones[1] != 0) {
			int sub = (stones[2] - stones[1]) / 2;
			ans += sub;
			stones[1] -= sub;
			stones[2] -= sub;
			if (stones[1] == stones[2]) {
				int m = stones[1] % 4;
				int n = stones[1] / 4 * 2;
				ans += m == 3 ? n + 1 : n;
			} else {
				ans += stones[1] / 2;
			}
		} else {
			ans += stones[2] / 5;
		}
		out(ans);
	}
}