A,B,C = map(int,input().split())

res = []
if C%A == 0 and C//A <= A/B:
    res.append(C//A)
if (B+C)%A == 0 and (B+C)//A > A/B:
    res.append((B+C)//A)
if not res:
    print(-1)
else:
    for v in res:
        print(v)