#include <bits/stdc++.h> 
#include <atcoder/all>
#define pub push_back
#define eb emplace_back
#define mp make_pair
#define fi first
#define se second
#define rep(i, n) rep2(i, 0, n)
#define rep2(i, m, n) for (ll i = m; i < (n); i++)
#define per(i, b) per2(i, 0, b)
#define per2(i, a, b) for (ll i = int(b) - 1; i >= int(a); i--)
#define ALL(c) (c).begin(), (c).end()
using namespace std;
using namespace atcoder;
using ll = long long; using dd = double;
using Pll = pair<ll, ll>;
using    vll = vector<   ll>; using   vdd = vector< dd>;
using   vvll = vector<  vll>; using  vvdd = vector<vdd>;
using  vvvll = vector< vvll>; using vvvdd = vector<vvdd>;
using vvvvll = vector<vvvll>;
using  vchar = vector< char>;
using vvchar = vector<vchar>;
using mint = modint998244353;
using mint2 = modint1000000007;
using  vmint = vector< mint>; using  vmint2 = vector< mint2>;
using vvmint = vector<vmint>; using vvmint2 = vector<vmint2>;

constexpr long long INF = (1LL << 60);
constexpr double EPS = 1e-9;
constexpr double PI = 3.141592653589;

//////////////////////////////////////////////////////////

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;
}

template <typename T>
T sq(T x) {
	return x * x;
}

std::string zfill(int n, const int width)
{
	std::stringstream ss;
	ss << std::setw(width) << std::setfill('0') << n;
	return ss.str();
}



int main() {
	cout << fixed << setprecision(10);
	ios::sync_with_stdio(false);
	cin.tie(nullptr);

	ll N, M, K; cin >> N >> M >> K;

	if (N != 0 && M != 0) {
		if (K == 0) {
			cout << -1 << endl;
			return 0;
		}
	}

	string S = "0", S2 = "1";
	ll a = 1, b = 0, c = 0, d = 1;
	rep(i, K) {
		if (i % 2 == 0) {
			S.pub('1'), S2.pub('0');
			b++; c++;
		}
		else {
			S.pub('0'), S2.pub('1');
			a++; d++;
		}
	}
	if (a <= N && b <= M) {
		a = N - a; b = M - b;
		rep(i, a) {
			cout << '0';
		}
		if (K % 2 == 0) {
			cout << S.substr(0, S.size() - 1);
			rep(i, b) {
				cout << '1';
			}
			cout << S[S.size() - 1] << endl;
		}
		else {
			cout << S;
			rep(i, b) {
				cout << '1';
			}
			cout << endl;
		}
	}
	else {
		if (c <= N && d <= M) {
			c = N - c; d = M - d;
			cout << '1';
			rep(i, c) {
				cout << '0';
			}
			if (K % 2 == 1) {
				cout << S2.substr(1, S2.size() - 2);
				rep(i, d) {
					cout << '1';
				}
				cout << S2[S2.size() - 1] << endl;
			}
			else {
				cout << S2.substr(1, S2.size() - 1);
				rep(i, d) {
					cout << '1';
				}
				cout << endl;
			}
		}
		else {
			cout << -1 << endl;
		}
	}
}