My WA approuch is, (please, help-me)
let n, c1,c2, v1, v2 (positives integers).
The Objective is minimize (v=v1*x+v2*y)
where n = c1*x + c2*y
x,y are integers >= 0
So, my idea is
From
1) n = c1*x + c2*y
I can write:
A) n - c2*y = c1*x
B) n - c1*x = c2*y
So,
A1) c1*x = n (mod c2)
B1) c2*y = n ...