package lesson_3;

public class Frame_13 {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		
		int[] data = new int[] {1,2,3,4,5}; 
		System.out.println(oddElementSum(data));
		System.out.println(oddElementSum(new int[] {3,3,3,3,3,3}));
		System.out.println(oddElementSum(new int[] {}));
		System.out.println(oddElementSum(new int[] {0}));
	}
	static long oddElementSum(int[] data){
		
		if ((data == null)||(data.length<2)) {return -1;}
		long sum=0;
		for (int index=1;index<data.length;index++){
			if (index%2 == 1){sum+=data[index];}
		}
		return sum;
		
	}
	}