/* -*- coding: utf-8 -*-
 *
 * 2247.cc:  No.2247 01 ZigZag - yukicoder
 */

#include<cstdio>
#include<string>
#include<vector>
#include<algorithm>

using namespace std;

/* constant */

/* typedef */

typedef pair<int,int>pii;
typedef vector<int> vi;
typedef vector<pii> vpii;

/* global variables */

/* subroutines */

string ps2s(vpii &ps) {
  string s;
  for (auto &p: ps) {
    int ch = '0' + p.first;
    for (int j = 0; j < p.second; j++) s += ch;
  }
  return s;
}

string calc(int d0, int d1, int n0, int n1, int k) {
  int ds[2] = { d0, d1 }, ns[2] = { n0, n1 };
  vpii ps;
  for (int i = 0; i <= k; i++) {
    int p = i & 1;
    ps.push_back({ds[p], 1});
    ns[p]--;
  }
  if (ns[0] < 0 || ns[1] < 0) return "2";

  int i0 = 0, i1 = ps.size() - 1;
  if (ps[i0].first != 0) i0++;
  if (ps[i1].first != 1) i1--;
  ps[i0].second += ns[d0];
  ps[i1].second += ns[d1];

  return ps2s(ps);
}

/* main */

int main() {
  int n, m, k;
  scanf("%d%d%d", &n, &m, &k);

  if (k == 0) {
    if (n > 0 && m > 0) { puts("-1"); return 0; }
    vpii ps({{0, n}, {1, m}});
    string s = ps2s(ps);
    puts(s.c_str());
    return 0;
  }

  string s0 = calc(0, 1, n, m, k);
  string s1 = calc(1, 0, m, n, k);
  string s = min(s0, s1);

  if (s[0] >= '2') puts("-1");
  else puts(s.c_str());
  return 0;
}