#include <bits/stdc++.h>
using namespace std;
#define FOR(i,m,n) for(int i=(m);i<(n);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()
using ll = long long;
constexpr int INF = 0x3f3f3f3f;
constexpr long long LINF = 0x3f3f3f3f3f3f3f3fLL;
constexpr double EPS = 1e-8;
constexpr int MOD = 998244353;
// constexpr int MOD = 1000000007;
constexpr int DY4[]{1, 0, -1, 0}, DX4[]{0, -1, 0, 1};
constexpr int DY8[]{1, 1, 0, -1, -1, -1, 0, 1};
constexpr int DX8[]{0, -1, -1, -1, 0, 1, 1, 1};
template <typename T, typename U>
inline bool chmax(T& a, U b) { return a < b ? (a = b, true) : false; }
template <typename T, typename U>
inline bool chmin(T& a, U b) { return a > b ? (a = b, true) : false; }
struct IOSetup {
  IOSetup() {
    std::cin.tie(nullptr);
    std::ios_base::sync_with_stdio(false);
    std::cout << fixed << setprecision(20);
  }
} iosetup;

int main() {
  int n, m, k; cin >> n >> m >> k;
  if (n == 0 || m == 0) {
    cout << (k == 0 ? string(n, '0') + string(m, '1') : "-1") << '\n';
    return 0;
  }
  if ((min(n, m) + 1) / 2 < k || max(n, m) / 2 + 1 < k) {
    cout << "-1\n";
    return 0;
  }
  string ans = "";
  if (n / 2 + 1 >= k) {
    ans += '0';
    REP(i, k) ans += (i % 2 == 0 ? '1' : '0');
  } else {
    ans += '1';
    REP(i, k) ans += (i % 2 == 0 ? '0' : '1');
  }
  const int ze = n - count(ALL(ans), '0'), on = m - count(ALL(ans), '1');
  REP(i, ans.length()) {
    if (ans[i] == '0') {
      ans = ans.substr(0, i) + string(ze, '0') + ans.substr(i);
      break;
    }
  }
  for (int i = ssize(ans) - 1; i >= 0; --i) {
    if (ans[i] == '1') {
      ans = ans.substr(0, i) + string(on, '1') + ans.substr(i);
      break;
    }
  }
  cout << ans << '\n';
  return 0;
}