public static int solution(int[] nums,int target){
		int start = 0;
		int end = nums.length-1;
		
		while(start+1<end){
			
			int mid = start+(end-start)/2;
			if(nums[mid]>target){
				end = mid;
			}else if(nums[mid]<target){
				start = mid;
			}else if(nums[mid]==target){
				end = mid;
			}
		
		}
		
		if(nums[start]==target){
			return start;
		}
		if(nums[end]==target){
			return end;
		}
		
		return -1;
	}