text: function solve(param) {
      let inputType = typeof(param);
      let result = 0;
  
      if(inputType === 'number')
      {
          result = (param ** 2) * Math.PI;
          console.log(result.toFixed(2));
      }
      else
      {
          console.log(`We can not calculate the circle area, because we receive a ${inputType}.`);
      }
  }
  
  solve(5);