#include <bits/stdc++.h>
//#include <math.h>
//#include<string>
//#include <atcoder/all>
//using namespace atcoder;
#define _GLIBCXX_DEBUG
using namespace std;
using ll = long long;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define rep2(i, s, n) for (int i = (s); i < (int)(n); i++)
#define rrep(i,a,b) for(int i=a;i>=b;i--)

#define V vector<ll>
#define Vi vector<int>
#define Vd vector<double>
#define Vb vector<bool>
#define Vs vector<string>
#define Vc vector<char>
#define VV vector<V>
using P = pair<ll,ll>;
using G = vector<vector<int>>;
#define all(a) (a).begin(),(a).end()
#define rall(a) (a).rbegin(),(a).rend()
#define INF 1LL << 60
template <typename T>
bool chmax(T &a, const T& b) {
  if (a < b) {
    a = b;  // aをbで更新
    return true;
  }
return false;
}
template <typename T>
bool chmin(T &a, const T& b) {
  if (a > b) {
    a = b;  // aをbで更新
    return true;
  }
  return false;
}

long long combi(long long n, long long k) {
  if (n == k || k == 0)
    return 1;
  else {
    return combi(n - 1, k - 1) + combi(n - 1, k);
  }
}
//整数かどうか
bool isNumber(const string& str)
{
  for (const char &c : str) {
        if (std::isdigit(c) == 0) return false;
    }
    return true;
}
//最大公約数
int gcd(int a, int b){
  if(a%b == 0){
    return b;
  }else{
    return gcd(b, a%b);
  }
}
//最小公倍数
int lcm(int a, int b){
  return a*b / gcd(a, b);
}

//int di[] = {-1,0,1,0};
//int dj[] = {0,-1,0,1};
//cout << fixed << setprecision(15) << y << endl;
//s = regex_replace(s, regex("あ"), "う");

/*//各桁の和
 int wa(int n){
  int sum =0;
  while(n>0){
    sum += n%10;
    n/=10;
  }
  return sum;
}
*/
/*
//階乗
 int ki(int i){
   int k = 1;
   for(int j = 1; j<=i; j++){
     k *= j;
   }
   return k;
 }
*/

//vector<int> dx = {1,0,-1,0,1,-1,-1,1};
//vector<int> dy = {0,1,0,-1,1,1,-1,-1};
//int dx[4] = { 0, 1, 0, -1 }, dy[4] = { -1, 0, 1, 0 };
//#define mod 998244353
//using mint = modint1000000007;
//cout << mint.val() << endl;
//using mint = modint998244353;
#define yes "Yes"
#define no "No"
#define Yes "YES"
#define No "NO"

int main(){
  int a, b, c;
  cin >> a >> b >> c;
  int an1,an2;
  an1 = c/a;
  an2 = (b+c)/a;
  set<int>st;
  if(an1*a == c && an1*a-b<=0)st.insert(an1);
  if(an2*a- b == c && an2*a-b>0)st.insert(an2);
  if(st.size() < 1)cout << -1 << endl;
  else{
    for(auto e : st)cout << e << endl;
  }
}