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

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

using namespace std;

/* constant */

/* typedef */

typedef vector<int> vi;

/* global variables */

/* subroutines */

void putv(vi &vs) {
  for (int i = 0; i < vs.size(); i++) {
    int ch = '0' + (i & 1);
    for (int j = 0; j < vs[i]; j++) putchar(ch);
  }
}

/* main */

int main() {
  int n, m, k;
  scanf("%d%d%d", &n, &m, &k);
  if (k > min(max(n, m), min(n, m) + 1)) { puts("-1"); return 0; }

  vi vs({n, m});

  if (k == 0) {
    if (n > 0 && m > 0) { puts("-1"); return 0; }
    putv(vs);
    return 0;
  }

  while (k > 1) {
    int l = vs.size();
    if (! (l & 1)) {
      vs[0]--;
      vs.push_back(1);
    }
    else {
      int c1 = vs[n - 2];
      vs[n - 2] = 1;
      vs.push_back(c1 - 1);
    }
  }

  putv(vs);
  return 0;
}