Can anyone help me understand where is the mistake, please?

package com.codegym.task.task04.task0419;
/*
Maximum of four numbers
*/
import java.io.*;
public class Solution {
public static void main(String[] args) throws Exception {
BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
String num1 = reader.readLine();
String num2 = reader.readLine();
String num3 = reader.readLine();
String num4 = reader.readLine();
int a = Integer.parseInt(num1);
int b = Integer.parseInt(num2);
int c = Integer.parseInt(num3);
int d = Integer.parseInt(num4);
if ((a >= b) && (a >= c) && (a > d)) {
System.out.println(a);
}
if ((b >= a) && (b >= c) && (b > d)) {
System.out.println(b);
}
if ((c >= a) && (c >= b) && (c > d)) {
System.out.println(c);
}
if ((d >= a) && (d >= b) && (d > c)) {
System.out.println(d);
}
if ((a == b) && (b == c) && (c == d)) {
System.out.println(a);
}
}
}