#include <bits/stdc++.h>

using namespace std;
void fast_io() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
}

int main() {
    fast_io();
    int n, m, k;
    cin >> n >> m >> k;
    if (k % 2 == 1) {
        if (n < (k + 1) / 2 || m < (k + 1) / 2) {
            cout << "-1\n";
            return 0;
        }
        vector<int> cnt(k + 1, 1);
        cnt[0] += n - (k + 1) / 2;
        cnt.back() += m - (k + 1) / 2;
        for (int i = 0; i <= k; i++) {
            for (int j = 0; j < cnt[i]; j++) {
                cout << i % 2;
            }
        }
        cout << endl;
        return 0;
    }
    if (n < (k + 1) / 2 || m < (k + 1) / 2) {
        cout << "-1\n";
        return 0;
    }
    if (n < (k + 2) / 2) {
        if (m < (k + 2) / 2) {
            cout << "-1\n";
            return 0;
        }
        vector<int> cnt(k + 1, 1);
        cnt[1] += n - (k + 1) / 2;
        cnt.back() += m - (k + 2) / 2;
        for (int i = 0; i <= k; i++) {
            for (int j = 0; j < cnt[i]; j++) {
                cout << (i + 1) % 2;
            }
        }
        cout << endl;
        return 0;
    }
    vector<int> cnt(k + 1, 1);
    cnt[0] += n - (k + 2) / 2;
    cnt[k - 1] += m - (k + 1) / 2;
    for (int i = 0; i <= k; i++) {
        for (int j = 0; j < cnt[i]; j++) {
            cout << i % 2;
        }
    }
    cout << endl;
}