import java.util.Scanner;
import static java.lang.Integer.max;
import static java.lang.Math.min;

public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int a = scanner.nextInt();
        int b = scanner.nextInt();
        int c = scanner.nextInt();
        int minFloor = min(min(a, b), c);
        int maxFloor = max(max(a, b), c);
        int middleFloor = a + b + c - minFloor - maxFloor;
        int resultFloor;
        if (31 * (maxFloor - minFloor) < 47 * (middleFloor - minFloor)) {
            resultFloor = minFloor;
        }
        else {
            resultFloor = middleFloor;
        }
        System.out.println(resultFloor);
    }
}