public class Map {

    public static class Pair {
        private Object key, value;

        public Pair(Object key, Object value) {
            this.key = key;
            this.value = value;
        }
    }

    Pair[] pairs;

    public Map(){
        pairs = new Pair[2];
    }

    public Map(int size){
        pairs = new Pair[size];
    }

    public void put(Object key, Object value) {
        for (int i = 0; i<pairs.length; i++) {
            if (key == pairs[i].key) {
                pairs[i].value = value;
            }
        }
    }

    public Object get(Object key) {

        for (int i=0; i<pairs.length; i++) {
            if (key == pairs[i].key) {
                return pairs[i].value;
            }
        }

        return null;
    }

    public void remove(Object key) {

    }

    public Object[] keys (){

    }

}