; Variable declarations
(declare-fun x () Int)
(declare-fun y () Int)

; Constraints
(assert (> x 0))
(assert (> y 0))

(assert (= (mod (+ (* 10 x) y) 7) 0))
(assert (= (mod (- x (* 2 y)) 7) 0))

; Solve
(check-sat)
(get-model)