text: // You are climbing a stair case. It takes n steps to reach to the top.
  
  // Each time you can either climb 1 or 2 steps. In how many distinct ways can you climb to the top?
  
  /**
   * @param {number} n
   * @return {number}
   */
  var climbStairs = function(n) {
      var n1 = 1;
      var n2 = 1;
      
  
      // n1 and n2 stands for how many ways it can reach n taking one step or two steps, such as n - 1 and n - 2
      for(var i = 2; i <= n; i++) {
          var ways = n1 + n2;
          n1 = n2;
          n2 = ways;
      }
  
  
      
      return n2;
  };