import sys
readline=sys.stdin.readline

A,B,C=map(int,readline().split())
ans_lst=[]
if (B+C)%A==0:
    ans_lst.append((B+C)//A)
if C-B<=0 and C%A==0:
    ans_lst.append((C//A))
ans_lst.sort()
if ans_lst:
    print(*ans_lst,sep="\n")
else:
    print(-1)