The Unity says I have compiler errors and it doesn't allow me to run the game but I can't find any errors in the code

using UnityEngine;
using System.Collections;

public class FlySpawner : MonoBehaviour {

    [SerializeField]
    private GameObject flyPrefab;

    [SerializeField]
    private int totalFlyMinimum = 12;

    private float spawnArea = 25f;

    public static int totalFlies;

    // Use this for initialization
    void Start () {
        totalFlies = 0;
    }

    // Update is called once per frame
    void Update () {

        //While the total number of flies is less than the minimum...
        while (totalFlies < totalFlyMinimum) {

            //...then increment the total number of flies...
            totalFlies++();

            //...create a random position for a fly...
            float positionX = Random.Range(-spawnArea, spawnArea);
            float positionZ = Random.Range(-spawnArea, spawnArea);

            Vector3 flyPosition = new Vector3 (positionX, 2f, positionZ);

            //...and create a new fly.
            Instantiate(flyPrefab, flyPosition, Quaternion.identity);

        }

    }

}