Error CS 0136 while writing Leap Motion Gesture control

Hi I m new to Unity coding and had seen a tutorial for the swipe gesture recognition using Leap motion and had written the code also but it is giving me a error on line
controller.EnableGesture(Gesture.GestureType.TYPESWIPE);
which i m not able to understand

I have been using Leap_Motion_Orion_Setup_win_3.2.1

A local variable named gesture cannot be declered in this scope because it would give a different meaning to 'gesture', which is already used in a parent or current scope to denote something else

the code which i had used is as follows

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using Leap;
using Leap.Unity;

public class GestureHand : MonoBehaviour {
Controller controller;

void Start () {
Controller = new Controller ();
controller.EnableGesture(Gesture.GestureType.TYPESWIPE);
controller.Config.SetFloat ("Gesture.Swipe.MinLength", 200.0f);
controller.Config.SetFloat ("Gesture.Swipe.MinVelocity", 750f);
controller.Config.Save ();
}


void Update () {
Frame frame = controller.Frame ();
GestureList gesture = frame.Gesture ();
for (int i = 0; i < gesture.Count; i++)
{
Gesture gesture = gesture;
if(gesture.Type == gesture.GestureType.TYPESWIPE)
{
SwipeGesture = new SwipeGesture(gesture);
Vector swipeDirection = Swipe.Direction;
if(swipeDirection.x < 0){
Debug.Log("Left");
}else if (swipeDirection.x > 0){
Debug.Log("Right");
}
}
}
}
}