/**
 * initialize your data structure here.
 */
var MinStack = function() {
  this.repo = [];
};

/**
 * @param {number} x
 * @return {void}
 */
MinStack.prototype.push = function(x) {
  if (!isNaN(x)) {
    this.repo.push(x);
  }
};

/**
 * @return {void}
 */
MinStack.prototype.pop = function() {
  return this.repo.pop();
};

/**
 * @return {number}
 */
MinStack.prototype.top = function() {
  return this.repo[this.repo.length - 1];
};

/**
 * @return {number}
 */
MinStack.prototype.getMin = function() {
  if (this.repo) {
    const copy = this.repo.slice(0);
    return copy.sort((a,b) => a - b)[0];
  }
};

/**
 * initialize your data structure here.
 */
var MinStack = function() {
  this.repo = [];
  this.minRepo = [];
};

/**
 * @param {number} x
 * @return {void}
 */
MinStack.prototype.push = function(x) {
  if (!isNaN(x)) {
    if (!this.minRepo.length || x <= this.minRepo[0]) {
      this.minRepo.unshift(x);
    }
    this.repo.push(x);
  }
};

/**
 * @return {void}
 */
MinStack.prototype.pop = function() {
  if (this.repo.pop() === this.minRepo[0]) {
    this.minRepo.shift();
  }
};

/**
 * @return {number}
 */
MinStack.prototype.top = function() {
  return this.repo[this.repo.length - 1];
};

/**
 * @return {number}
 */
MinStack.prototype.getMin = function() {
  if (this.minRepo.length) {
    return this.minRepo[0];
  }
};