Java Programs easy way

package java2;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.HashMap;

import java.util.Map;

import java.util.Set;

public class met{

      public static int output1;

      public static void fn(Map<Integer, String> m1) {

            int count = 0;

            Set<Integer> s = m1.keySet();

            for (Integer i : s) {

                  if (i % 4 != 0) {

                        count++;

                  }

            }

            output1 = count;

      }

      public static void main(String[] args) {

            Map<Integer, String> m1 = new HashMap();

            m1.put(2, "hi");

            m1.put(4, "hello");

            m1.put(8, "abcd");

            fn(m1);

            System.out.println(output1);

      }

}