import java.io.*; public class Solution { public static void main(String[] args) throws Exception { BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in)); int a = Integer.parseInt(bufferedReader.readLine()); int b = Integer.parseInt(bufferedReader.readLine()); int c = Integer.parseInt(bufferedReader.readLine()); double average = (a + b +c)/3.0; double a2 = Math.abs(a - average); double b2 = Math.abs(b - average); double c2 = Math.abs(c - average); double d = Math.min(a2, b2); double e = Math.min(d, c2); if (e == a2) { System.out.println(a); } else if (e == b2) { System.out.println(b); } else if (e == c2) { System.out.println(c); } } }