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.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.StringTokenizer;

public class R {

	public static void main(String[] args) {
		FastReader fr = new FastReader();
		int a[] = new int[3];
		a[0] = fr.nextInt();
		a[1] = fr.nextInt();
		a[2] = fr.nextInt();
		Arrays.parallelSort(a);
		int result = 0;
		if (a[0] == 0 && a[1] == 1) {
			System.out.println(a[2]);
		} else if (a[0] == a[1]) {
			System.out.println(a[0]);
		} else if (a[2] == a[1]) {
			System.out.println(a[2]);
		} else if ((a[1] - a[0]) % 2 == 1) {
			result += a[2] - a[1];
			result += a[1];
			System.out.println(result);
		} else {
			result += (a[1]-a[0])/2;
			result += (a[1]+a[0])/2;
		}
	}


	static class FastReader {
		BufferedReader bf;
		StringTokenizer st;

		public FastReader()  {
			bf = new BufferedReader(new InputStreamReader(System.in));
			//bf = new BufferedReader(new FileReader("p.txt"));
		}
		String next() {
			while(st == null || !st.hasMoreElements())
				try {
					st = new StringTokenizer(bf.readLine());
				} catch (IOException e) {
					e.printStackTrace();
				}
			return st.nextToken();
		}
		int nextInt()  {
			return Integer.parseInt(next());
		}
		long nextLong()  {
			return Long.parseLong(next());
		}
		double nextDouble()  {
			return Double.parseDouble(next());
		}
		String nextLine() throws IOException {
			return bf.readLine();
		}
		boolean ready() throws IOException {
			return bf.ready() || (st != null && st.hasMoreElements());
		}
	}
}
