a,b,c = map(int,input().split())

ans = set()
if (b + c) % a == 0:
    ans.add((b + c) // a)
if c < b and c % a == 0:
    ans.add(c // a)
    
if len(ans) == 0:
    print(-1)
else:
    for s in sorted(ans):
        print(s)