import java.util.Arrays;
// From http://codingbat.com/prob/p138907
public class Group5Sum {
    public static boolean groupSum5(int start, int[] nums, int target) {
      if (start >= nums.length) return target == 0;
      int val = nums[start];
      if(val % 5 == 0) {
        if(start+1 < nums.length && nums[start+1]==1)
          return groupSum5(start+2,nums,target - val);
        else
          return groupSum5(start+1,nums,target - val);
      } else {
        boolean res = groupSum5(start+1,nums,target-val);
        if(!res) res = groupSum5(start+1,nums,target);
        return res;
      }
    }
    public static void test(int[] arr,int sum) {
        boolean res = groupSum5(0,arr,sum);
        System.out.printf("groupSum5(%s,%d)->%s%n",Arrays.toString(arr),sum,res ? "true" : "false");
    }
    public static void main(String[] args) {
	   test(new int[]{2,1,5},7);
       test(new int[]{5,1,1},7);
       test(new int[]{5,1,1,1},7);
       test(new int[]{5,1,2},7);
    }
}