import java.io.*; import java.util.*; public class Main { public static void main(String[] args) throws Exception { Scanner sc = new Scanner(); int[] values = new int[3]; for (int i = 0; i < 3; i++) { values[i] = sc.nextInt(); } int left = 0; int right = Integer.MAX_VALUE / 2; while (right - left > 1) { int m = (left + right) / 2; int current = 0; for (int i = 0; i < 3; i++) { if (values[i] < m) { current -= m - values[i]; } else { current += (values[i] - m) / 2; } } if (current < 0) { right = m; } else { left = m; } } System.out.println(left); } } class Scanner { BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); StringTokenizer st = new StringTokenizer(""); public Scanner() throws Exception { } public int nextInt() throws Exception { return Integer.parseInt(next()); } public long nextLong() throws Exception { return Long.parseLong(next()); } public double nextDouble() throws Exception { return Double.parseDouble(next()); } public String next() throws Exception { while (!st.hasMoreTokens()) { st = new StringTokenizer(br.readLine()); } return st.nextToken(); } }