HINTS:

(2+3) = QRNQYVAR 
(2+5) = ONAGRERQ
(2+11) = NZRAQRQ
(5+7) = JNGREORQ
(7+8) = JURRQYRQ
(11+12) = QEHZORNG

(3) = QVNY
(4) = YVQ
(5) = OENG
(6) = ONE
(7) = JRRQ
(8) = URYQ
(9) = YRQ
(10) = JRQ
(11) = ZNQ
(12) = OEHGR
(13) = GHOR
(14) = EHOR
(15) = ZNVQ
(16) = NQ
(17) = QRA


SOLUTION: SNGURE GVZR