import sys
def input():
  return sys.stdin.readline()[:-1]
A,B,C=map(int,input().split())
ans=[]
if C%A==0 and C//A*A==C and B>=A*(C//A): ans.append(C//A)
if (B+C)%A==0 and A*((B+C)//A)-B==C and B<A*((B+C)//A): ans.append((B+C)//A)
if len(ans)==0: print(-1)
else: print(*ans,sep='\n')