Java

Main.java

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int a = in.nextInt();
        int b = in.nextInt();
        int c = in.nextInt();
        System.out.println(Math.max(a, Math.max(b, c)));
    }
}

Always close the scanner once you're done with it.

in.close();