/**
 * @param {number} capacity
 */
var LRUCache = function(capacity) {
    this.capacity = capacity;
    this.cache = new Map();
};

/** 
 * @param {number} key
 * @return {number}
 */
LRUCache.prototype.get = function(key) {
    if(this.cache.has(key)){
            let value = this.cache.get(key);
            this.cache.delete(key);
            this.cache.set(key,value);
            return value;
        }
        else{
            return -1;
        }
};

/** 
 * @param {number} key 
 * @param {number} value
 * @return {void}
 */
LRUCache.prototype.put = function(key, val) {
    if(this.cache.has(key)){
            //refresh the cache
            this.cache.delete(key);
            this.cache.set(key,val);
        }
        else{
            if(this.cache.size===this.capacity){
                this.cache.delete(this.cache.keys().next().value);
            }
            this.cache.set(key,val);
        }
};